Hey guys/gals. I've started from scratch and never bought donuts to get stuff. I play this game too much, so I'll give ya'll some tips.
To start, I have gotten all my money by filling up my land to the brim, by buying as many brown houses as possible. After making that profit every couple minutes, I'd buy more land, and install more houses. It gets big and full. Then once my savings accumulated enough legitimate money to buy more expensive houses, I moved on to purple houses ($75 every 3 hours is pretty good)
From there I built up to blue houses ($150 every 8 hours pretty decent), then white, and now I'm moving on to orange houses (which make $250 every 16 hours). My town is now pretty large, I have all the available items (excluding the $1,000,000+ ones), many of the characters, I leveled up quick, and with the houses I have only check my game every 12 hours.
IMO this is the quickest way to level up and make the most money. I now make about $150,000 every 24 hours.
It's an old inside joke not really worth explaining, but most importantly, it makes people laugh and remember!