I like creative money makers. Woodworking, painting, writing, playing music for tips, telling jokes for tips...
I also use collecting and frog breeding to get a sim started in money making (those sims that start at zero funds always collect and breed frogs until they can afford an easel, guitar, computer, or whatnot).
Gardening is a good money maker, but I don't have a lot of gardener sims, as I find the gardening a bit boring. I think that's part of my RL view on gardening, though.
I have had sims get large loans from other sims. My actress sim, with max charisma, got a loan from her director and co-stars, but, she did have an actual job, too (actress).
Fishing is fair, if you can start getting some sturgeon's.
I wouldn't say any of them are unusual, but those are my favorite ways to make money in game. Most time, unless a challenge tells me to, I rarely play careers. About once every 10 or so sims will have a regular job.
