Tent carpet, good airbeds and sleeping bags, a folding loo for night-time and nice reliable and comfortable chairs. I ought to add "space" too, especially for longer stays so you can spread out....
------------- Love our set-up and need no more tents or gear, so trying to stop looking!
I know you wanted lights/furniture, but I've got nothing special in that department. My car's full enough as it is, & I'm a solo camper with a large saloon car! (& only basic kit, just lots of it!)
I agree that it doesn't need to be colour matching to be comfy - and not even tidy. When I travel solo, I have space in the car for all the colour matching luxury things, and the tent looks like this:
... but when I travel with the kids, it is a completely different thing - still comfy, but looks more like home...
------------- Proud owner of a 1987 Sprite Alpine 370 EK, a cheap popup tent and a beloved retro Trio frame tent from the early seventies, called Giraffen.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.
Topic: how comfy?
