Forgot to say "buy a fixie". However, make sure it's not a proper usable one like a Genesis or a Langster. Get something old, knackered and difficult to buy parts for, just make sure it's 531. Pay at least £300 for the frame. Put moustache bars on (stupid shape), no bar tape (uncomfortable, cold), Campag pedals and clips (difficult to get in and out of), cottered cranks (just a general pain in the arse) and no brakes (unsafe). Bang on to anyone who will listen about the "track geometry" whilst coming up with reasons that you've actually never had a go on a track. Pootle around Shoreditch at 6mph because you're scared to go any faster. You should put cards in the spokes, though you're not sure why.