Really just a couple things you need to be aware of. First, if your P226 is DA/SA, you need to have grips with the decocker lever cut out. Second, screw length. You want to make certain the screws are the correct length. Too long and they will extend into the mag well and impede insertion/removal of the mags. Too short and you will have less thread engagement, increasing the chances of the frame threads stripping out. I like for the screws to reach the bottom of the threaded holes of the frame. If your grips came with screws, odds are they are the correct length. If not, just a bit of caution will save you some heartache.