Don't believe all the ramp rage stories. Over the years I've found most people are pretty calm around boat ramps. Everyone is generally pretty helpful.
Before you arrive at the boat ramp think about what you are going to do before you get there.
Most boat ramps have a rigging area. Only use the boat ramp to launch. Use the rigging area to prepare your boat, put on your suncream etc.
If you can back a trailer great. If you need practice do it somewhere else.
Most boats and jetskis or PWCs have bungs. Put them in before you leave home.
When you drive off or return, keep it slow. Creating wash can cause damage to other boats and is a sure way to upset other boaties.