I do so many projects that I imagine will be GORGEOUS when finished but then the actual execution is not how I imagined. It doesn't upset me too terribly. It's part of the process of design. You have to try things out, see how they look and then make adjustments until it's right. For me, the process is just as important as the result. The process - the making, creating, designing part - is the fun part.
I do enjoy my creations when they're done but there are many projects stuck in drawers waiting for fixing. And even though I don't use those imperfect projects, I don't regret the time I spent on them because I learned something from each of them. I enjoyed my time with them. I don't throw them away because one day I may find the solution that will finish the project the way it was meant to be. A project can't be forced. It has to wait for it's time to become what it was meant to be. Kind of like life.