Post more often, post interesting stuff.
Let things happen naturally.
Don’t ask for tips, post about … Tupac, and someone who appreciates Tupac or rap will tip you.
Don’t wait for your art to sell … Keep posting your art, maybe different ones and maybe give some story. What is it? What inspired you? Put it up for sale! ( and those who know how, can post about that )
Don’t ask why people don’t see, you go show it to them!