First you have to cut lengths of fabric, twice as wide as the bias tape you want to make. The gizmo came with one head but you can (and my daughter did) get extra heads to make different widths.
You then take your strip and clip it onto the spindle and wind it on by hand:
The tricky part is threading the end of the tap into the tape head. I find pushing it through with a blunt ended darning needle in the top slot to be easiest.
Then, once the machine is turned on and warmed up, which only takes a few minutes, it's a very simple matter to place the tap across the ironing plate, bob the top on and press a button.
It took me a couple of goes to get everything just right, but once you have got the hang of it, it makes tape making a real doddle - and it's fun!