I've used the tips posted by topcat and anty with success ... I would add a few other things that could be helpful ...

It took me a while to find the right clips, as I also had problems with large, heavy clips still flopping down over the hairline. My stylist finally gave me some small (about 2 inches long) light metal clips ... the kind women used years ago to "set" wet hair into a wavy style. These work better for me. They hold the hair tighter, enough that I have to be careful when removing them not to tear hair out ... the hinges can catch hair as well.

So if I manage to keep hair out of the glue when attaching or touching up the front, it can still be an ongoing problem if I've "overshot" the glue at the hairline. Here's where another tip I read about (Jrob, I think?) really helped. I'll use a small loop of sellotape (or "scotch" tape as we call it here in the states), wrapped around the ends of two fingers, sticky side out. I apply this right up to the edge of the base at the hairline and ... "right off like a bandaid." This works well for removing excess glue, you'll see it on the tape. I would add that a magnifying mirror, or a pair of strong reading glasses helps a lot w/ this fine detail work ... also to avoid pulling the edge of the base up w/ the tape.

Hope this helps,
~FB