I recycled a shelf, threw some 24” + 10” plywood on it connected with hinges, so it’s a futon during the day and I pull the plywood out making it a flat 32” bed for nighttime, and attached little wooden peg-legs that swing up from halfway up the shelf to catch the lip of the plywood.
She’s got a kitchenette, fridge, sink, awning, solar panel, and she’s the biggest little campervan I’ve ever seen