Forget those clips ... you mean those things that look like staples, right?
I went to Home Depot and bought some #4 3/8-inch sheet-metal screws (3/16-inch would've been better, but the smallest they had was 3/8). Using the pre-existing holes that were already in the felt strips (and one I drilled myself, at the end of the curved tip), I laid the felt strip in place on the window moulding and drilled holes into the moulding using a 3/32-inch drill bit. When I screwed all down tight, the screw heads got buried in the felt - you can't even tell they're there! Lastly, I cut the ends of the screws off with my dremel -- they looked like they were sticking through the other side too far. Another reason I used screws instead of the staples is, I plan on covering my inside window mouldings with vinyl and will have to remove (and replace) these felt strips when I do that project -- staples would've been a pain in the neck, eh?
You can check out my step-by-step install
HERE ... see #10 about those staples/clips.
