Kicking is my bread and butter, I consider it like counting coup on my enemy. I will rarely try a risky kick, the only sure fire way to land one is this:
Baiting: after exchanging a blow or two, slowly back away in a straight line. If they follow you suddenly stop and kick, this way they walk right into it. I can't even count the number of times this has worked for me, even against folks who know what I am trying to do.
A riskier kick is if you are fighting a slow enemy that is in fact too slow to chase you, after backing away slightly, lunge forward and swing, this will freeze them usually for a second, and since you can attack and kick before they counter attack, you are likely to catch them mid swing. This worked great for me as a bardiche user, but is riskier as a sheilder.