Currently I'm sleeping on a ghastly old futon, until I can find a daybed that both suits and is affordable.
Recently I discovered a couple of ideas that I may combine to create the look I want for my bed/couch:
I like the look of this bed, and the storage underneath. From Small Space Style.
This DIY from Apartment Therapy: Boston would play off the bed above for an inexpensive DIY.
I notice both are tucked into corners. At a guess, it helps to stabilize both the mattress and the frame.