Key elements

1 Access to plenty of fresh air - for obvious reasons

2 Lots of spare everything: loo paper; towels; soap

3 Good light, whether natural or artificial

4 A mirror: give your guests a chance to preen

5 Surfaces that are easily cleaned and maintained

6 Add a few extras - like some decent handcream, and a waste basket, and something to read other than a dog-eared magazine dating from the mid-1980s.