I still use white-out and will sometimes physically paste panels onto a page. Since I’m really a novice when it comes to Photoshop it’s easier and faster to bust out the scissors and glue!
One neat side effect of this is that I’m hoping it will make the pages easier to sell someday, since they pretty much look exactly as they do in print.
This is, of course, assuming they weather the ravages of time. The only stopping me from selling Box Office Poison art is that I used sharpies to fill in the blacks so they’ve aged terribly. Let this be a warning to you, kids!