Enough cupboard space to store food. Its self catering, I need to be able to store the food I will be cooking. So many places seem to think it's great that they have provided every single kitchen utensil you can think of, all the cupboards and drawers in the kitchen are rammed full of stuff. I turn up with a weeks worth of shopping, where do I put it?
More plates, bowls, glasses, cups, cutlery than there are beds. So annoying if there is only 1 plate and 1 glass per person.
If you provide a washing machine, some way of drying things that is not a tumble dryer. Either indoor clothes racks or an outdoor clothes line. If it's an outdoor line, it needs pegs too (more than 3 pegs).
Must be spotlessly clean.
A decent guide to the local area, not just your favourite restaurant (though by all means point out the best ones). It's nice to have a choice of all types of eating places, not just the ones the owner likes, we might like something different. Things like where nearest supermarket, pharmacy, doctors, A+E are. Then touristy things and local walks. Train/bus time info. A guest book is also helpful if people can be encouraged to recommend what they did during their stay that was good. Tide times if you are near the coast.
A way of contacting the owner or whoever can sort out problems. We stayed in a place that said Mr X lives on site and can help you. But there were about 20 different houses 'on site' and no phone number for Mr X. He never popped in to introduce himself, so how the heck were we meant to contact him? Knock on all the doors until we found the right one?
I would highly recommend staying there for a few nights before you let it to customers, stay in both rooms and use the wardrobes, drawers, bathrooms, kitchen etc. That the only way you will find out if door handles are broken, lights don't work, the curtains in x room don't quite close, the pans don't fit on the hob, or the shower won't work if the washing machine is running, that the bedside lights are too bright/dark for the room, there aren't enough plug sockets, a door creaks or a drawer is a bit stiff etc etc