If you make furniture, it should also be noted, that it's usually more comfortable than the furniture, in build mode. If you have the time to make it, you might want to replace whatever you are using for dining chairs & sell off your original chairs, one by one, then later replace whatever you're using for a dining table. After you've done this, you might be at a skill level, where you can get more from selling the furniture. It also takes a while, before making furniture stops hurting you.
Whenever you make a chair that's more comfortable than the one that you're using, sell the one that you're using & keep the comfy chair. This will keep your guests pleased. Crafted items seem to take a little less time to construct, than paintings take to paint. The profit isn't as big initially, though. I usually max painting first, and let it support me, while I learn & level crafting.