The only wall my bed fits on there's a window.

Are you trying to cover the window?

Its a personal choice matter.

you might want one that lets the window show, like open metal frame, such as the one in our photo, see photo, it is not in front of a window, but it could very well be there

Do you have to open that window? If not- I wouldn't necessarily worry about limiting your headboard considerations.

We used to have our bed under a window, but only moved the roller shade up and down. We opened the window as needed on the other wall and used a ceiling fan. We had light airly white voile curains on both windows.

Pallets

My bed is under a window. And I don’t like the cold air I feel from it, old windows; I’m in an apartment.

I would use / easily make a big padded headboard (see TV show- the Middle - parents bedroom) if you have to have a headboard at all.

I don’t, but I have good insulating curtains

I use a sofa table that is the width of the king bed and just to the height of the window sill. Pillows still stand up against the table so I can read. Works for me and I use the table for my lamps instead of side tables.

Can you center the bed under the window and use that as your "headboard"?

Put plastic over the windows to keep out the cold. With your insulated curtains, it should keep out the cold. If not, try making drapes out of fleece throw blankets.

www.apartmenttherapy.com/pull-it-off-beds-in-front-of-windows-199055

my bed is against two windows. Although we live in Maine, I do not notice cold from my windows. I use an antique bed frame, double size. My husbands bed is also against a window. He has one of those bookcase head boards. Works great as he gets to keep books there and also can use one of those mattress/springs on the Harvard frame. Our granddaughter has a room in the attic which is unheated. Her bed is also against the window. I did make kind of a slip cover for the head of her bed, and used to hang velvet curtains in the winter.

Hang a large curtain rod over the window and use the window as your headboard---- have the curtains frame the bed.