Do exactly as instructed in the video and you won't go far wrong. Having watched it a week or so before my window film arrived, I thought I had all the know-how tucked away in my head, but halfway through fitting the first cut piece to one of my windows I ran into difficulties. My memory was not as good as I thought it was and I managed to waste my first piece due to getting it stuck to itself! My fault, and I cannot blame the 'tools'. On watching the video again I realised my mistake. I did not remove the clear backing whilst spraying the sheet with soapy water, before taking it to the window to set in position. Fortunately I anticipated the odd mistake and had ordered sufficient length to ensure I still had enough for all windows. One thing I would add, which might help some. If fitting window film with a geometric pattern to square / oblong windows, do make sure the pattern lines up with your frame. I was able to adjust mine just in time before it became a little tricky to move. Although the film will slide on the glass quite easily, overlaps (before trimming) have a tendency to 'grab' their surroundings, particularly UPVC window frames. I am delighted with the overall finish and effect. I have done away with some ugly old net curtains and now just need to fit a Roman blind to complete the job (to do away with some old-fashioned curtains!) I give Window Film Direx 5 out of 5 for quality, shipment time and price, and for their detailed video of how to go about the job for a professional finish. Just do remember to watch it!