I like using a mattress pad. And, although the tops are always nice and padded, the sides are either way too tight, or, like my last one, made of some sort of pantyhose type material that started running the first time I washed it. I've actually broken fingernails while wrestling on a mattress pad. They've been driving me nuts for years.
Recently, we wore out my favorite easy-to-put-on fitted sheet and I had a light bulb moment. Why not just sew the mattress pad top to the fitted sheet? Well, it wasn't easy, but it's totally worth it, because now it's super easy to put the mattress pad on now.
Here are the steps I took:
1) Cut the sides off the mattress pad so you are just left with the pad.
2) Put fitted sheet on the bed and lay the mattress pad on top.
3) Pin the mattress pad to the fitted sheet using a ton of pins. Take care to not pin the whole thing to the mattress (like I did a couple of times).
4) Sew around the edge of the mattress pad.
5) cut out the center part of the old fitted sheet that is under the mattress pad. I did this partly because the sheet was already fraying and partly to not have too many layers covering the mattress and keeping it from breathing.
I didn't do a perfect job, but it's hidden under the sheets, so no one except me (and you) knows. The best part is that the mattress pad doesn't *snap* off while I'm making the bed or sneak off the corners in the middle of the night anymore. Yay!