I once for a year ago or so won a turnamnet for about $300 and decided to move up from 2nl to 10nl (I were a winner at 2nl). I went about break even for a month or so and then i busted almost my entire bankroll (I cashed out the last and stopped playing for some months).
Now I started playing 5nl and also playing freerolls and have right now built up my bankroll from $100 to $2500 (about 1.7k from freerolls, yes I have been lucky
). Even though my big cashes from turneys I learned from my misstakes and did not move up from 5nl until I were up about 20BI's , then I took a 5 BI's shoot at 10nl, failed, moved down, built it up again and is now up about 20BI's at 10nl.
Dont do the same misstake as me, play 2nl until you have reached 20BI up or something similar and take a shot at 5nl.