The thing nobody tells you before you buy a double bed is that the mattress and the frame need to agree on support, not just size. A cheap slatted base with the slats spaced too far apart will eat a good mattress alive in a couple of years, sagging in the middle no matter how much you paid for what's sitting on top. Check the slats before anything else. That's the whole trick.
In an ordinary bedroom, a double sits best with something low and simple nearby, a pair of small side tables rather than anything bulky, because a double already takes up real floor space in most rooms built for one person who then invites someone else to share it. If you're starting from nothing, go with a plain wood frame, solid if you can afford it, a good birch plywood if you can't, but avoid anything described as wood veneer over particleboard that doesn't tell you what's underneath the surface. I spent two years sleeping on a frame like that, bought in a hurry during a move, and watched the headboard joints loosen until I could rock the whole thing with one hand. The frame I replaced it with was half again the price and has not moved an inch in six years, through two apartments and one very enthusiastic dog. That's the real gap between cheap and good here, it's not about looks, both frames looked fine in a room, it's about whether the joints are actual joinery or just screws into soft board that strips out the first time you have to take it apart to move house. A double also suits a smaller bedroom better than people expect, since the frame itself is compact if you choose one without a huge footboard, and it works in nearly any kind of home, a rented one bedroom, a guest room in a family house, a studio where it's doing double duty as a couch during the day. Where it struggles is in rooms under about ten feet wide, since you lose the walking space on either side, and in houses with narrow staircases, which nobody thinks about until the frame is stuck halfway up on moving day.
Seasonally it's an all year piece, nothing about a bed frame changes with weather the way a sofa fabric might, so don't let anyone sell you a "summer" or "winter" version, that's just marketing on top of furniture. The one mistake to avoid is buying the frame and mattress from two different sales without checking they're actually built for each other, a slatted frame with the wrong gap will void some mattress warranties outright, and you won't find that out until the mattress is already sagging and the receipt is long gone.