House farming isn't necessarily necessary to earn good money in this game...I never did it because I didn't like the look of it. As an alternative, if you have the time (which is a big "if"), try sending your characters on the shortest tasks you can manage. Fortunately/unfortunately, when I first started playing this game, I was bedridden and out of work on disability, so I was able to use mostly 1-hour tasks throughout the day. Even now, I generally use a couple of sets of 4-hour tasks, followed by a round or two of 1-hour tasks during the day/evening, then put everyone on 12-hour tasks overnight. (Although, I have to admit to getting much more lax lately and not always doing all of those things, but, then again, I'm at the point in my game that I have enough cash and donuts to pretty much do/get anything I want.)
Also, having a high bonus multiplier is the key to wealth in this game...when you do earn donuts, and there isn't something pressing and time-limited you really want to buy with them, spend them on the original mystery boxes, which have the best return in terms of bonus multiplier to donuts spent. Every set of 25 boxes will earn you 9% (except for one shorter pattern...shorter than 25 boxes...which will earn you 6%. You can hide the news vans and billboards (the bonus earning items that you get from the mystery boxes) behind buildings and large decorations or just shove them into one corner of your town. If you have room for the Lard Lads you earn, and don't mind having an ugly Lard Lad "farm," those can help you to earn cash, too. (Personally, I don't like permanent-type farms, like house farms or Lard Lad farms, because I like to have a nice-looking town, so I have a couple of hundred Lard Lads in storage.)
And be sure to keep your collider charged up at all times...unless you're at the very lowest levels of the game, it's almost always worth the cost, especially if you're KEM farming.
But all of these are just strategies, not mandates....to me, the most important thing is to do whatever brings you joy in the game.