Step 1: Check for loose springs. A trampoline bed with loose springs is like a teenager with acne - it's a mess.
Step 2: Tighten those prophets. Use a trampoline wrench or a hammer to tighten those springs until they're snug as a bug.
Step 3: Inspect for wear and tear. If your trampoline bed is starting to look like a used tissue, it's time to replace it.
For more information on trampoline bed maintenance, see: