Plant your flag. Stake your claim. Mark your territory.
If you get to your gig early enough, you will be able to solve a multitude of problems that wandering in closer to your performance time will never allow.
When you arrive make sure you have the space you need, the furniture you need, the most optimum performance real estate - being sure you are seen and heard. Do your mic check. Set your props on stage if you can. Find a private place to change if the client hasn't provided one.
Getting early to a gig means you can relax and enjoy your experience on stage with piece of mind that you've put out the fires before they had a chance to ignite.