If it’s a slower serve I prefer to cut it off before it hits the glass to eliminate the possibility of a weird, spinny bounce. If it’s a faster serve that’s harder to do. In these cases, the mistake I made early on (and see other newbies making) was positioning my body too close to the glass and then kind of getting stuck in the corner with no room for a proper swing. Make sure to stand a few feet back from both the side and back glass, with your body facing the side glass, and just keep your eye on the ball knowing it’s going to ricochet back up to you…at which point you play your backhand or forehand shot. If it barely pops up off the back glass, leaving you little opportunity for a clean direct shot, then you can play it back off the side glass. Harder to do as you have to get the angle just right, but when you get it down it can be a great way to return as it really throws people off.