This might sound like a basic place to start but begin by ensuring that your bike is always in good working order, keep an eye on tyre tread, brake blocks and cable tension and all of the moving parts of the ‘drivetrain’ (chain, chainrings, derailleurs and cassette). Always seek professional advice if you are unsure about bike mechanics.
Spend some time finding the best possible riding position and bike set up. An ill fitting bike could cause you to be less efficient on race day and therefore lose time, it also can lead to injuries if you are not suited to the bike. The bike should be made to fit you, not you to fit the bike. Comfort is absolutely key when riding a race bike.