I only play with my own money. I built a bankroll playing freerolls. I follow the bankroll management system and therefore always keep my emotions under control. It would be psychologically difficult for me to play with money that does not belong to me.
I regularly play freerolls, thus increasing my bankroll, and with the money I win, I play buy-in tournaments. The system is very simple but effective if you follow the bankroll management system.
I play with my own money and with freerolls. For example the cardschat freerolls and the sunday million freerolls from pokerstars are very nice but it's for sure not enough so I play with my own money as well.