Add your design on products, get percentage of sales. Completely free.....
I've been getting about $200 a month from Zazzle and Cafepress combined. Every now and then, I'll get close to $400 for one month, that's usually when seasons change from winter to spring. As long as you create plenty of content(and I mean a lot) and be creative with designs or words, you'll eventually see your stuff selling on the regular. I still have stuff selling that I created over 5 years ago.
I probably could be making even more if I put even more effort into it.
Lotto Pick 3 ............
I play $10 a day on the evening numbers. I get 5(pick 3) numbers a day. $5 going towards straight(winning number must be in sequential order) and $5 going towards box(can win in any order). That's about $300-310 a month.
Winning straight on a number is $500, winning box is $250. Since I buy both straight and box of the 5 numbers I play, every time I hit I get 500+250 which is $750.
So being that I spend up to $310 a month, the profit from $750 is $440. I usually win twice a month about 4-6 months out of the year. So that profit is now $1190 for those months I hit twice. There's about 2 months every year that I don't win anything.
Blogs and Youtube .........
If you can bring enough traffic to your blog or have plenty of Youtube views and subscribers, you can make some decent money. I don't do this myself, but I know some who do.