What are the top three (humorous) things a person can do to avoid butt-dialing?

Pad the butt in carbon-fibre armour so there is no pressure on the phone when seated.
Design variations drawn from various themes; medieval knight, ballerina's tutu, workman's hi-vis helmet, etc.

While wearing the armour, sitting is not so comfortable.

Use a flip phone.
Use a waist holster.
Lock the phone.
Don't use a mobile.
Don't carry a smartphone on your body at all.

I can only think of one.