As some of our racers will be soon trying a few longer TT's here are some of my top tips.
I firmly beleive anyone can complete 25 miles in less than 60mins, it's easily within the capability of most, beyond that then improvements would be specific  structured and intense short training efforts to knock a few mins off and beyond that all down to genetics.

The bike, you don't need a super aero all singing carbon 5grand beast, a standard tubed steel will do just fine with some simple modifications. My first  59:59 was on a Raleigh Low Pro, 650 front wheel, 16 spoke, 50mm shamals front and back, tubs, single chainring at front, no front mech, cut down cinelli  tempo low pro bars, TI stem, standard SLR brake levers, cut down Profile Aero bars, cut into two separate bars, TI post and saddle, side pull cheap brakes.

Weight saving, you will hear some say weight matters little on the flat when upto speed, well there are such things as headwind, drags and riders not blessed  with natural high power outputs - in these cases for the lesser power rider these all matter a lot. It's all about kinetic energy built up and stored in you  and bike, the stored energy helps to propel you and maintain speed, if you stop pedalling or micro ease off peddaling during each rev, the forces of  resistance against you (wind/road/friction etc) are minor in comparison so you don't slow very quickly. Riders with lesser power lose out a lot more against  the wind and up drags as you have less kinetic energy built up than the naturally more gifted faster rider has AND you have to keep dipping into your red  zone a lot more as the resistance against you gets harder the more you try to push your legs - you just hurt and tire more than the faster rider.
Further your leg muscles fire much differently against resistance than for example when you have a tailwind (training against tough winds is not the best  type of training for you at all), it looks to be the case for slower riders that each rpm you have slightly more time duration to fire the muscle and you  must do so to overcome the resistance hence more energy used compared to the higher power rider and hence it just seems to get harder and harder against the  wind. That longer time duration of firing the muscle means you are working a lot harder. So, ride controlled and smoothly the best you can hold.

Worth mentioning too your speed against the wind is fixed v however strong your legs are, some can do 20mph against a wind and others 22mph, you cannot as  often banded about just increase your power against the wind, reasons stated for this are you can afford to lose power on the tailwind leg and overall will  gain time. Well, the maths is correct but if you can up your power against a wind then you are clearly not riding at your threshold in the first instance and  it must be your first ever race ! A negative pacing is the best and only way over to ride, ie set off steady and build up and increase all the way throughout  unless you happen to be riding a TDF 5 mile prologue then it's max from the off and hang on.

Equipment, components light as possible, you don't need a super comfy saddle, get a light one for an hours riding, carbon seatpost aero one perhaps, or just  get a light cheap one and cut down excess seat post weight. Tri bars, cut these down fore and aft (don't want to bang your knees-it hurts a lot !) , same for  drops you don't want big curly stuck up ends into the wind either. Run your cables inside your bars, most come pre-drilled, if not easy to drill and run  through. Use TT specific aero brake levers that run the cable through the bar from the rear of the lever, cheap and light as well. Gear levers, thumbshifters  on ends of the TT bars, set to friction as always nice to tweek the smoothness. Calculate your gear ratios and find out your favourite ones, naturally you  will use only a couple in a race that your type of muscle fibres like to turn, if you use a bigger chainring you can use more of the sprockets at the rear  that are in the middle of the cassette and get a smoother chainline. Tape your TT bars up only where you hold them, drops not needed. Bottle cage, not needed  for an hours ride unless baking hot and you do suffer. Pump, get a small mini pump, affix it with tape, clips whatever out of the wind, mine is mounted to my  bottle cage holes on the top not the side. Unless you like long walks in your cleats then easy to fit a small seat pack jammed right under your seat with a  tube and levers, continental seat pack my favourite. Quick releases, get some steel or titanium allen skewers instead, clean lines and lighter, you will need  to carry an allen key (not for horizontal rear drop-outs). Pedals if you can afford lighter ones then do so. Calipers, save weight and use sidepulls, there  are some good ones on the market, or some fancy aero front calipers are available too. Personally I do like to spend money on the lightest cassette, dura ace  for me always good weight saving and will last a long time on a TT bike.

Wheels, disc and some form of multi 3/4 spoke carbon front probably the fastest  combo money can buy and for not so calm days a deep rim front, if not a good matching pair of deep rims from a known brand, less spokes the better - spokes  create turbulence, one of the best front wheels ever made and useable in any conditions was the Corima 12 spoke, generally most have 16/18.

Tyres, speed to be gained here, go for normal tubes for decent puncture protection with fast TT specific tyres, my favourite Continental Supersonic clincher  with the matching supersonic tubes, these are light yet seem very durable and genuinely feel fast when you ride them, worth a spend here. If the course is  decent surface then a few extra psi but mostly over inflation will mean skipping and a less smooth ride over our rough roads, remember it is rims that have a  PSI rating so don't over inflate past your rim specs.

The race, it's 25 miles around an hours riding at your one hour threshold, if you have done plenty of training at a few bpm below this for hour long training  sessions then you will be ready, race for an hour train for an hour, that is what your body will go through in a race, it's not about the fast speed or the  pain intensity, it is about holding the SAME effort from start to finish suffering the same. This is why all training for TT should reflect what you will  expect your body and legs to go through in the race. Training for an hour where you hold the same effort is hugely harder than riding for an hour where you  vary your efforts going hard for a while resting up a bit, giving it some again, slowing into the wind as you've already goosed your legs etc.

The wind, you will face long periods against and with the wind, remember what I said above. Riding into the headwind, keep low down at the front, don't  overgear, cog down and rev through it, concentrate on holding your best effort, look ahead for where the conditions may briefly alter, random topography  changes that will affect you, exposed sections will be tough, gaps in hedges gusts of wind, passing traffic turbulence, be ready to ride through these  without easing that effort off, brief dips in the road take advantage and accelerate down. Tailwind this is the key, most will not go fast enough here, very  easy to cruise and come off the gas. Riding and training properly fast with a tailwind is hard very hard, probably more uncomfortable than a headwind, it is  completely a different physical effort, your leg muscles will fire differently than they do against a headwind. Against a headwind you will run out of leg  power, with a tailwind there is far less resistance working against your leg muscles so you can use your aerobic system and probably going anerobic (10 pace)  to support your legs moreso and get far more out. This is where you will recoup and gain some time if you are not suffering more than the headwind section  then your probably not going fast enough.

Clothing, a good tight fitting skinsuit, if you have the cash an aero specific one, fit your number tightly or have one those number pockets fitted so you  can just drop your number inside. Lycra oversocks or some aero dimpled ones. There are aero mitts available too, best to have mitts for better grip too. Aero  helmet that sits nicely on your head when in the TT position, as long as it does not stick up at the back should be fine. If it has a visor use an anti-mist  on the inside. Shoes, plenty of aero type shoes around now, lace ups as well for more aero.

Position, low as you can without hampering your breathing but the main thing here is to be rock solid throughout, this is so important, any body movement  disrupts the air flow and your effort, you must keep your upper body still at all times, hard when your suffering but a time gainer.

Setting off, build up and then concentrate on that same maximum effort you can hold, for a progressive start I always simply use my gears as opposed to  setting of in a big gear, churning it upto speed then suffering with latic and catch-up breathing. So, away in something you can accelerate say, 53x17, rev  it out, up one, rev it out up one, until (and you will know) when your legs cannot go up another, in other words the next gear up will be a windmill churn !  Concentrate hard and hold your HR bang on for all but the last five miles where you can start to get everything out, wind it up and up all way to finish, cog  another gear and give it all, finish at hill climb effort.

3  x 20min 10's
34 x 21min 10's
94 x sub 60min 25's
6  x sub 2hr 50's