For bedding, we wrap each mattress section in its own fitted sheet. Before retracting slide, the top covers get folded back onto footboard section of mattress leaving the headboard section free to flip over. Pillows are placed on top of the flipped over headboard section.
We don’t use a toad so have retracted slide everyday on week long trips several times. With a little practice, it goes very quick.
On our 22M we leave our 4" foam top and bed clothes on the mattreses. We Slide the back mattress up and over the front mattress, folding the bedding and foam between the two. You can't Flip the back mattress up an over as it will hit the two window valences on either side of the slide. We have added two short dog leashes to the hand loops on the back mattress to facilitate the ability to pull and slide the rear from an easier position up and over the front one.
I agree with Bilfsey, gets pretty easy with a little practice. His custom individual fitted sheet for each piece is a nice trick. But we find that the mattresses are pretty hard and need that foam.
No way does our method look as neat as Eagle5's photo. So if you are a neatnick, you may want strip the bed and make up each night. But then where do the bedclothes go, and fitting that back sheet is quite a pain.