Hi there
You could frame them for the wall (if you have space and are 'allowed' of course)
Put mine in a box frame, cover the backing with an appropriate colour felt (the patch velcro sticks to the felt) and that's about it. Small box frames are relatively cheap
If the box frame is too deep build the back out with MDF and cover that in the felt. If too shallow make a spacer out of beading picked up cheaply from the likes of B&Q
Example below - although a 'box' frame there was no space between the glass and the backing so made a spacer out of some beading and sprayed it black
57th Rescue Squadron Patch Collection - June 2019 by
Darren Currie, on Flickr
NB - have been advised that it is best to have a space between the glass and patch - if condensation is permitted to build up between the glass and patch it will over time rot the patch
Failing that, just remove the glass from a frame and cover the back in felt. You can then swap patches around whenever you want (see below)
67th SOS 'Night Owls' by
Darren Currie, on Flickr
Hope that helps some
Darren