You have to have two sims to do this and this is for 3ds. First have one sims do something that they will be able to gain skill, make sure the bar is over the their head when you switch to the other sim, then have the other sim stand right next to them. Next put the speed on three then have the sims doing nothing call someone but when you go to the meun that lets you chose which person to talk to, don't click noone and the sim who is gaining a skill, the skill bar will go up faster.