What works best for me is to make the home button the top. Then I align the screen protector with the home button and top edge. Once I have it perfectly aligned then it flows nicely down the rest and also is aligned on the sides and then also when it gets to the other edge. Really important to do both perfect home button and edge. This is for a flexible screen protector. If you use a glass screen protector, it is stiff enough to hold straight across the full iPad and then align both the home button and further hole as well.