Step 1: Get your stuff
-tape measure (cloth sewing tape measure is ideal)
-reflective fabric (this needs to be wide. i used 4" wide fabric which wraps around a 1 1/8" diameter tube with a nice overlap. It didn't quite make it on the downtube which is fatter. There's a little gap on the underside. I ordered the fabric from identi-tape.com but i'm sure there's other places to get it.
-a bike (older steel bikes are ideal, no fat tubes or funny shapes)