Unfortunately it just comes down to training. I've got to admit that as a junior, with no specific tt training but quite a lot of cross and mtb racing I did 26.30 first time, so it's just fitness in general I reckon.
With a bit of training (road riding - never turbo) I got that down to 21.20 but I was much fitter then (15 years ago). It's all about targeting a distance, I used to do 20 mins warm up, then flat out for 12 miles or so, then 20 mins warm down, in between big road and mtb rides the rest of the week.
No specific aero stuff apart from tri bars with no arm rests (to get lower) and a super light Giant Cadex 980C.
Ah past glories. Got overtaken by a bloke on a hybrid with panniers this morning - and I couldn't be bothered to chase....