make (one's) bed (up)
1. To tidy or rearrange the bedclothes on one's bed after one has slept in it. Would it kill you to make your bed in the morning? It only takes a couple minutes! I never feel like I've properly started the day until I've made my bed up.
2. To prepare a bed for one to sleep in by fitting, arranging, or tidying the bedclothes on it. Your brother and sister are in the two spare rooms, so I made your bed up in the living room. Be sure to make each guest's bed before they arrive.
make one's (own) bed
1. Lit. to restore order to the bedclothes on one's own bed. Jimmy, you are old enough to make your own bed.
2. Fig. to be the cause of one's own misery. Well, I guess I made my own bed. Now I have to lie in it. "We all make our own beds," said the minister.