SECOND, if you don't have any skater friends or any way to get any, is to make your own! Get a friend who doesn't skate, or your girlfriend, parents, really anyone who will help. Have them read over the step by step instructions for the trick, and also the instructional skate trick video (for example, how to ollie instructions, and have them watch learn how to ollie video too). Then have this person watch you try your trick, and give you feedback of what they think you might need to change. I know that this might sound ridiculous, but it can work! Back when I first started skating, my brother and my mom helped me out, and neither of them knew how to skate. The point is that someone else might be able to see something that you don't even know you are doing!
THIRD, if those options won't work for you, you can get a camera or a phone and film yourself trying to do the trick. Take that video and upload it to YouTube, with a name like "need help landing my kickflip" or something like that. Other skaters can see it then, and help you out! You can post your video to forums, to the about.com skateboarding facebook page, and you can even email a link to me and I can give you some advice. Be sure to get several angles of you trying your trick.
I truly do hope that these help. The only thing left to do is to keep trying, watch more instructional videos, check out our skateboarding FAQs, and maybe take a break and try a different trick, then come back and try your trick again.