Well, I think the most projects you do you discover new ways to do things. For these reason i think know new languages or frameworks can help you with your old legacy code.
For this reason i think you always have to go straight and advance in knowledge, and the most technologies and libraries you see you can take ideas to refactor your old projects.
Another idea is to read documentations, examples and screencast about the clean code and decouplement of code, and when you have more knowledge, return to your old project and apply!
for other side, you projects always can be better and for this reason i think always change and adapt to the new ideas.