Hi Karen,
After the crosstitch is pinned, wrap the extra fabric neatly to the back and tape down.Do not trim it. Put it the frame, another piece of board (or cardboard)is placed over it, press down firmly and secured with framing points or tiny nails etc, The back of the frame is sealed with sturdy paper. This is glued in place over the entire back to seal then trim off the extra paper 1/8 in from outer edge. Mount hangers 1/3 down from top of frame or put a metal toothed hanger at center the top. On larger frames I prefer the hooks and wires. I hope this answers your question. Maybe one trip to a framing shop would help. I like to mat the cross stitch with coordinating colored matting, it really sets off your work.It sounds like a lot of work but it will last for years. A good piece of cross stitch is worth a good frame. Note: Be sure the glass is spotlessly clean and no dust particles inside before closing the frame