Are you leaving them a little runny? That's basically the trick to any egg. They'll continue cooking after you take them off the heat, and in the end won't be dry and tasteless.
I've done a little experimenting and found that the best results for me come with the eggs well cooked on one side (with small browned areas) and runny/custardy on the other side. I fold it so the runny part is in the middle.
