Make sure you use a good lash glue. A tip I read online is to ensure the glue is tacky before you try and stick your lashes down. The glue supplied in my kit was really watery and just wouldn't hold my lashes in place. In the end, I dashed to Superdrug and bought a lash glue which worked so much better.
Take your time in sticking your lashes in place. Mine kind of clumped together, so the next time i do them, I'm going to stick them down a couple at a time to ensure they are straight.
All in all, I was pretty pleased with them. It wasn't brilliant, but a good first attempt.
Good luck.