I used to suck at saying "No", but once I realized that nobody else seems to mind saying: "Here, you fix my problem" it became a lot easier. Plus I have important things to work on anyway.
Exactly. Saying no also becomes a lot easier the more you do it. Hell, it's actually become my default answer to any request anyone makes of me.
The really cool thing about saying no to people though, is that if you say no to people enough they eventually just stop asking you for things altogether. Then you don't even have to say no to people anymore since they kinda say it to themselves when they consider asking you for help.