Instead of spray glue I use 3M Weather stripping glue. I apply it with a small acid brush on both the headliner and flange. It's much easier to manage. Follow the instruction's.
I also instead of using those small clamp's, I use wind lace cut up in 3-4 inch section's. Wind lace is used in Classic Mustang interior's to finish off the panel edge's. It will clamp the headliner much tighter than those clip's. They will not fall off.
Pictured is a 1969 GTO headliner that I'm installing. The (white) wind lace can be seen on the back, front and driver's side edge of the headliner. The passenger side is not pulled tight yet.
I also use the screw trick. Much easier to find the screw's than looking for the hole's.