Prostitution > Spa > Cafe (after remodel) > Farm are the jobs I've found that can easily pay back the full Baily amount for two people each week when you want to get passed desperation mode to pay, lol.
You can start Prostiution with no skill, just spam Seduce attempts at people sitting in the Pub till you can get A-S rank overall, then start asking them for 50-100 dollars each attempt. Skullduggery allows you to steal more from them each attempt.
Next level is Brothel work, which is a bit riskier and eats up Fatigue faster I think, but can be worth about double each attempt quickly. You'll need to get your Dance skill high for that too. Once a week Brothel shows are worth a lot as well, and the Gloryhole in the basement is the easiest/safest way to train up sex skills, so it's a good place to hang out for a lot of reasons.
Next is Spa work, my favorite. You need max Seduction, Hand, Thigh or Butt skills and high Promiscuity and Exhibition to get max profit, but it's the fastest way to earn a ton of money. You can make over 500 in an single massage/edging session, though sometimes you'll earn around as low as 100 too. I think the average is around 250 at least and it's a 50 minute job instead of 1 hour like most places, so it's a bit better than it seems.
Pretty easy to make several thousand there for a full day of work, but it does take 2-3 weeks of training Seduce and sex skills at the Gloryhole to be really great. It's also one of the most reliable high paying jobs because there aren't any gimmicks with it that can prevent working there all day and it never shuts down (It's how I paid for all the damm Farm upgrades lol). Pretty safe too, nice that it's near home as well.
Then there is the Cafe, which is really only profitable after months of work (including it being shut down completely for 30 days). After raising love with the owner enough, you'll have to boost your max semen amount by having near max arousal with full balls and passing time (3-6ml increase an hour usually with high arousal), or just ejacalulating a lot (3ml per ejaculation). Lactating and/or having the Cow transformatation makes it way better if you want to go all in, but it can be pretty profitable even as a normal boy. Just be careful of suspicion...
Farm is probably only profitable after like a year and a half. It's so expensive to upgrade everything that you'll be in the red for a long time even after you unlock all the fields, so it's not recommend for casual play, but it's probably the best money making method long term.
Oh, and with high Promiscuity, you'll have more control over sex posititons. At level 5 you can posititon people pretty much however you want. Good place to test it is the Gloryhole, where at level 5 you can train any body part there. Thigh and Nipples are from moving to give a blowjob/positioning you genitals over their genitals, then pulling away. Sometimes they'll thrust towards you again, so you might need to pull away multiple times before Thigh/Nipple posititon is available.