I can tell that even after just a few quilts - well, lets be honest - a few UFO's - that I have gotten better. I am still very careful to choose things I think I can realistically do and they are nothing like most I see here :)
Don't worry - its the process sometimes not just the final product. We put so much time into these quilts the creating has to be fun!
And - no one notices the mistakes you might on your quilt. :)
I can't tell you how much of a difference each step makes. Don't skip the washing fabric before you start. I learned that the hard way - now I always prewash.
And to get corners to line up, I have one seam go one way and one the other so they "nestle" up together. Works like a charm!