If you want something easy, small, and pretty..perhaps try peacock gudgeons
I have not encouraged mine to do anything.
Only gave them good food, clean water, and decorations to squeeze into as they like tight places.
The mom and dad are in a 20g and I moved the male and decoration to a 10g, once they hatched I took the male back out and now I have lots of adorable fry. My first fry ever ^_^