You can actually do a tip jar. I probably should stop saying this, because no one pays any attention. Sigh. But, honest, it can be done.

http://micheleincalifornia.blogspot.com/2015/11/how-to-make-...

I don't make a lot of money via tips -- and some of my sites still have ads -- but I make more via tips than ads. I think as I get more traffic, I will get more tips. And I would rather have my audience support my writing than some "sponsor." At some point, I might also do Patreon.