Tips on Tying Your Boat to the Dock | Boating Safety Tips, Tricks & Thoughts from Captnmike
Check out his "docking strap". It is simply a strap that with two loops that is setup to be the length from your mid-ship cleat (or primary winch) to the stern cleat on a dock, with a long extra line that you can use to control it. I took my brightest colored docking line and put a bowline in the middle to make the second loop. The bright color makes it easy to find.
If you snag the aft dock cleat with that and leave the boat forward in idle it will hug up against the dock and not go anywhere.
I have a 29.5' boat (with bow pulpit) in a 30' slip with my fiberglass standing up on the dock at the end of the slip. This setup has made docking a lot easier and more reliable for me.
His blog is worth reading for other tricks too.