Are all the parts tight and in good repair?
Check that the frame fits you
Are they fully inflated with plenty of tread and no bald patches?
Check spokes are not broken or loose and that both wheels run freely
Is the chain oiled and not too loose or too tight? Check all gears can be changed easily. Fixed gear bikes are allowed
Does the bike have two working brakes which stop the cycle with the minimum amount of pull on the brake levers?
Are the brake levers positioned so your fingers curve easily around them whilst the palm of their hand is on the grips?
Is the saddle straight, roughly horizontal and the correct height for the rider?
Is the saddle the correct height for the rider with the seat post tight and not over the maximum limit?
Have you checked for cracks, frayed straps and that it conforms to BS EN 1078:1997 or equivalent?