If you just want a community lot that'll attract enough foot traffic for your sim to earn tips, you could skip the custom lots and park her in front of the bookstore. This has always worked for me in SV and Riverview; after six to eight hours or so, my musician might have 20 sims listening and tipping. Obviously, sims stop showing up after a certain point, but a lot of them will stay until after midnight if my sim keeps playing.
Also, I don't know if you've seen, but the value of tips goes up each time your sim performs a song. You can spam this as much as you want—the "performance" counts towards the total even if the sim barely took out the instrument. But the tipping can spiral way out of control. I had one teen do this right after he maxed out his guitar skill, and he started earning §30k each day after school.
