Fantastic advice from all here. You've got to go out to the lawn and practice, that's the best way to get the entire process worked out. But, the most important thing to do after applying all the other advice...

...Relaaaxxxxx....... Just take it easy and enjoy watching the line glide out in front of you and then float down to the water's surface like a leaf. Go slow and gentle into your final forward cast. It sounds like you're trying too hard to get that perfect presentation. In this case; Less is more.

I still, after nearly 6 years of casting, let myself get worked up into a frenzy when I spot a fish in the water. I false cast great, then overpower my final cast as a result of the excitement, trying too hard. After the frenzy and frustration subside (usually many bad casts later) I realize that I'm trying to make too much work out of my hobby. That's when I relax and my presentation becomes more smooth, easy, slow, gentle and relaxed.

P.S. Don't forget to breathe. If you begin to pant, your cast will fail.

Hope this helps.

Tim