Hanging pictures

Screws…two through the frame and just through the inside wall. Not the prettiest but, hey, I’m campin’.

Gorilla double sided tape. It seems to hold up better than other tapes. But if you want to remove the pictures, the tape will damage the wallpaper.

Adhesive back Velcro works really well.
I buy the industrial extra strength. Apply both velcro sides to the picture frame, peel off the backing on the remaining strip, and then press onto the wall.
Works fantastic and is long lasting. Our pictures have been up for years.
Can easily be removed by carefully taking down the picture by wiggling it from side to side, and then slowly peeling off the velcro strip remaining on the wall.

We use the Command strips, but also put a small brad through the one on the wall side to provide additional shear support. Haven’t had a problem with them coming off in ~7yrs and ~60k miles of travel in two different 5ers

MNRon has the answer in my opinion. This is what we do. Small stuff, just 3M strips. Heavier stuff, 3M and a screw or nail, depending. Watch the length of the screw/nail...don't want it poking out the other side!

Did you use four Command strips per picture? Wood frames plus bouncing puts a load on the strips.

If you use Command Hooks, why not just take the pics down when you travel?

Lyle