Hello there,
I believe anyone who is persistent in his games, meaning to play calmly and patiantly over a long period of tournaments can build you a decent bankroll.
I think It's good to set some objectives too, because when you have order in your mind, you are much more focused on doing your best to achieve that goal. For example: I set a target, playing freerolls when I have the time in order to reach 50$. Then, I have two options: withdrawing it or starting to play micro buy-in tournaments for building a much more high bankroll, let's say double it, then withdraw.
But that requires discipline, seriousness and perseverance. I mean not winning let's say 2$ from a freeroll and then immediately start playing a 2$ buy-in torunament in order to gain more money fast. That won't work for your bankroll, or maybe work in that moment If you're lucky to win but bot on the long term.