I tuck the sheets and blanket in at the foot as I would do for any other bed. I do hospital corners and then let the sides hang, because I like the look better than tucking everything in all round.
If you have a blanket on top, you could do without the hospital corner on the blanket if you choose. At the corners of the footboard, there will be a "drape" of sorts. That's the way it's supposed to look.
Over my sheets I use a down-alternative blanket, and a quilt serves as my bedspread. The trick is to have the overhang and drape even on both sides (assuming you can walk about the bed) so everything looks intentional.
I never had a footboard-style bed growing up, so this was something I had to figure out how to do, too.