It's a little difficult to describe but easy to see. Portions of the Halloween costume below where foam-core meets PVC on the chest harness were attached using this homemade clip. This costume build and some other PVC mechanisms including a rotating hinge and linear joint is described in creatrope.com's general grievous costume.
To make a clip you need you the thin-wall version of the PVC tube. There's a thick-wall and thin-wall version - the thick will is usually my base for 'structural' elements, but the thin-wall makes a nice clip and is lighter.
Step 1: Cut Piece of Thin-Wall PVC, Align in PVC Cutters
Holding it vertically (and carefully) in the tube cutter rest the blade against the tube. This isn't how a tube cutter was designed to be use so work slowly and carefully, it's easy to slice a finger.
Make sure the cuts are straight vertical.
You'll make two cuts, about 120 degrees (1/3) of the tube circumference apart.
This produces one cllp (throw away the remaining 1/3).
Step 2: PVC Clip Complete
This clip is removable and adjustable. You can slide it as well.
By cutting off more or less than 1/3 you can adjust the 'strength' of the clip.
You can now glue things to the clip.
I've created several other PVC mechanisms during the creation of this costume. Please see creatrope.com's general grievous costume for more details.