I recently printed the Mini Base and added on the Big Drawer for it. Since that particular model is pushing the Mini's ability to print overhangs, the grip-hole didn't come out particularly precise. It also can't be enlarged anymore to fit my fat fingers - not that I'd want to remix and reprint 25 hours just for a hole that's a little bit bigger. Plus, the overhangs were already challenging with the original size.

So I tried to model a handle that slots into the hole.

Since I'm new to the game and fairly stupid, I also tried to challenge myself:

1. I wanted to design the whole thing in TinkerCAD, since I'm trying to get better aquainted with it.
2. I wanted it to be printable without supports, since the drawer itself doesn't need them either.
3. I wanted it to snap into place without any need for glue or screws, since the Mini Base doesn't need that either.

My first two prints failed. I redesigned. The print failed again. I gave up and used supports. 

Things I've learned from this disaster:

1. TinkerCAD isn't really useful for complex geometries that aren't at fixed angles. Challenge 1 failed.
2. If you want your model to print without any supports, you better start planning the final shape accordingly. Hollow parts and steep angles aren't really helpful. Challenge 2 failed.
3. If your measurents are right on, you can press-fit things without needing glue. Challenge 3 achieved.
4. Even a correctly tuned Prusa Mini doesn't print stable single layer borders. Game over. 
5. My fingers are even fatter than that. But I think it still looks nice. 
6. I'm an idiot who was in way over his head (see above). So if anyone with more skill than me wants to redo the concept in a proper CAD program, be my guest. I might return to it much, much later…

It actually works now, if placed on the insertable part, then printed with supports. It's a tight fit in my drawer, but if yours has cleaner overhangs, you might need glue. Printed in PLA, like the rest of my Mini Base and Big Drawer. Should fit the mini hexagoin inserts by pick_nicker, although you might need to scale them down a hair in the slicer (I haven't tried yet).