There is something to be said for earning tips...lots of tips. That seems to definitely help as you said. Still can't claim what it may be but, a combination of friends and tips can't hurt.
Though, I have another question...having an issue with asking to join a band. My band, three members, all level 10 in their respective instruments, they've had 6 gigs so far and all are registered at city hall with band as their employment. There are four Sims living together. I'm trying to ask the 4th Sim to join the band (I've tried all 3 band Sims) but, the option doesn't show up. I've tried asking townies, as well, with all 3 and the option doesn't appear either.
I'm curious if there's a bug, or if anyone knows as to why? I had the fourth register at city hall with band as her employment. She can ask other Sims to join a band, but not the 3 she's living with...puzzled. Thanks.