On days that I'm fishing alone instead of tying up tight to the dock I use a bow line and let the boat float out away from it. This keeps the boat from getting bounced into the dock and it keeps the boat out of reach from anyone that's hanging around while you park your truck/go get the truck.

If the wind or current is wrong so that it pushes the boat toward the dock or shore, stop 15ft or so from the dock and drop an anchor out the back of the boat and then pull up to the dock with your trolling motor and attach your bow line to the dock. The anchor rope has enough stretch that it will pull the boat back out from the dock while the bow line keeps it in place.

These methods have worked well for me and have kept my gelcoat on the boat instead of on the dock!

Dan