The "be patient" part is excellent advice. I don't know which video you watched, but the best one that I have seen is Derek Brown's (available from Kaufmann's), Hugh Falkus' book, Spey Casting, is excellent as well. I've been speycasting for a number of years now and still consider myself far from expert, but I assure you the skills will come in time. Slow down and don't overpower the cast. I'm sure you've heard the one about the guy in New York who walked up to a fellow with a violin case at the bus stop and asked how to get to Carnegie Hall. The violinist turned, looked at him for a while and said "Practice, practice, practice".