How can I make sure that I wax all of the hair off my upper lip?

I used wax strips before and I missed some hairs so I had to tweeze them. Any advice on how to get them all?How can I make sure that I wax all of the hair off my upper lip?
Are you dead set on waxing? If so, move on to next answer...if not, but you want all the hairs gone then I know a different way. I use a cream remover by GIGI made for your face. You can buy it at your local Sally's in the hair removal/waxing section. You wet the place where you want to remove hair, put the cream on that area, wait 8 minutes then wipe off. The package I bought came with this cream to use afterwards to calm your skin. I used to wax but I ran into the problem you have and another where I have super sensitive skin and might have a tiny pimple come on the waxed area...hurt like a mofo! Anyways, I like the cream. It's really easy to use and you can't really miss any spots. Good luck to you.