I have always made the frames for my canvases (with exception of those for my Minis). They are simple, elegant and, I think, suit my work ver well. Galleries and collectors concur.
However, they are now challenging to make since I no longer have my great woodworking shop. This becomes quite a (messy) production when making shadow box frames for three 36"x48" canvases going to gallery.
These frames are for stretched canvas panels on 3/4" stretcher bars.
I buy clear pine (comes from New Zealand!) 1.5" x .75" x 96". Trim to rough size, cut the miters, join/glue, add corner braces, sand everything outside and then paint (it takes five coats of the special silver/gold paint I use). I attach the canvases with screws (so can be easily removed ) and then add the hanging hardware.
The end results make the effort and attendant mess well worthwhile.