Use silicone glue on the corners from any hardware store. Its a youtube pro tip, it adds a bit of extra oomph so it doesn't just fall outfrom various qualities of adhesive strips. You can also use regular clamps with rubber jaws typically found in woodshops. We usually use the plastic cheap kind and they work. Most likely you will need the larger variety of clamps, however you could just put like paper towels inbetween the clamps and screen as a protector from scratching/damaging the screen as well.