I am so annoyed by those people that tighten springs by hooking them a few loops up, leaving the rest of the spring that I don't cut my springs. It's not evil or anything to cut a spring, just one of my pet peeves, I guess. I have turned one end to add tension, but it's not like the old thing suddenly springs back to life. It is pretty limited how much tension you can add that way.

Usually a good cleaning solves most of my spring problems. If not, I always try to have some new springs on hand. If a new spring doesn't solve the problem, then I know that there is another problem lurking in the midst.