I've found that on my quest to create the cheapest possible fidget spinner without much quality loss, printed bearings are not that bad, and 2ROBOTGUY's designs are the only ones that work well. So I found a ball bearing that works well, (still experimenting with this https://www.thingiverse.com/thing:53451 and this https://www.thingiverse.com/thing:2333792) scaled it up as far as I could, and stuck it in the center of the two of his designs that I use. They spin really good and I can do this to any design you want, just post a link to it in the comments.
High infill would be good, but you need small layers for the best results, and that means it would take forever on high infill.
Add bearings or pennies and start spinning!