If you are getting an open on certain pairs, that means you need to go back, clip off the ends, which I am guessing if you have not done before reterminating, you will never get it to work.
What I do, is will either use the back of my drywall knife blade to push down the wires a bit, or use the little tool, which works for a couple of times, to get the wires seated. It is more of an art than anything, and practice works to get it right.
Make sure that you have plenty of light, when doing the terminating of the keystones, and keep the diagram right there, or print off a larger size picture of a 566b connection, and take your time, even if it takes you longer than two minutes. I can do a keystone in probably a minute from start to finish, working with a patch panel takes a little longer.