For an easy to remove, yet secure mount:

• Cut out a substrate, I often use a piece of 1/4″ ply substantially bigger then the footprint of the pi so that I can screw /  glue other things to it as well as so that I can mount the whole shebang inside a case or wherever.
• Drill 4, 3/16″ diameter holes in a 3/4″ thick piece of wood… space them out far enough that you can cut a block around each one
• Cut each hole out, leaving a block of wood around it
• screw stand-offs onto each corner of the pi-zero
• put a drilled block onto each stand-off
• put a dab of glue / hot-melt glue onto the bottom of each block and then place the pi/blocks down on the backer that you want it all mounted on.  

When choosing where and how high to mount the pi, consider access to the sd card, the power ports / all ports and the desired height off the substrate.  More height gives more ventilation.

Also consider the wifi antennae and try not to block it ( as well as the gpio pins, if you are using them)

Hot gluing a super magnet cup to the backer board, away from the pi, makes it easy to secure the plate to metal, or a washer mounted where ever you’d like.