One of the r/Bonsai  guys posted a picture of a mame that inspired a lot of conversation.  I am copying some of his information here so that I can find it when I want it.

• I started by growing a field maple in open ground for 3-4 years.
• Chopped it down as low as you see here.
• It then burst out with buds (branches)
• I put it into a bonsai pot and it now essentially stays this big.

It’s important to pick a species which back buds and has small leaves.

Someone asked about watering something so small and his response was:

Humidity tray – semi-submerged or fully sometimes.

Here

I don’t know that I’ll ever try a mame but that humidity tray looks like a great idea, especially when we go out of town for a couple of days.