The shape of your trampoline completely changes how it feels to jump:

Check the warranty! A good brand will offer at least 5–10 years on the frame and 1–2 years on the mat and net. If the warranty is only 90 days, it's probably not built to last.

Ensure it is made of high-quality UV-resistant material. Ideally, the net should attach inside the springs/rods so the jumper can’t even touch the frame.

Do you have a specific or a size in mind for your backyard?

Look for galvanized steel (to prevent rust) and thick tubing. A "wobbly" frame is a red flag for poor quality.