Trash bag clip

I recommend printing from PETG, but it works even with PLA. Set wall count to 5, then use your favorite settings. If your bin has a large edge or you want stronger clips you can edit Fusion 360 file to fit your needs.

Using it, is simpler than printing, just put a trash bag in a bin and secure it with a few of these clips (just like in the photo below). It worked with just 3 but it was more secure with 4. It's also good to roll up the excess part of the trash bag outside and hold it with these clips.
 

This model is based on a real product, which broke easily because of cheap plastic, so I 3D printed this as a replacement.