A frame support, wooden dowel inside the pvc (expensive but worth it especially if it's cold the pvc cracks easily). metal supports to hold the a frame in. then metal brackets banged into place. and L metal brackets to hold the support. Here's a video of my rails that you'll be able to pause and see. they lasted forever through winter and thousands of sessions. The flat bar was the worst cause it didn't have a single support beam but instead stacks which you'd trip over. pre drill all the screw holes.
Enjoy
https://www.youtube.com/watch?v=ZCiPBbjWCRs