What guests really notice

Owners tend to worry most about the sofa and the artwork on the walls. Guests rarely mention either in their reviews. In our experience, there are other details that make the difference between a five-star review and a four-star one.

First impressions start with arrival. A guest who has to stand on the street at night with a suitcase, trying to find the entrance to the apartment, will remember that for much longer than anything inside the flat. Clear instructions, a photo of the entrance and a lock that opens without a phone call can prevent most of these problems.

Then comes sleep. A mattress that is too soft or too firm, thin curtains or a bedroom facing a noisy street regularly show up in reviews. A good pillow, meanwhile, is one of the simplest and most affordable improvements you can make to an apartment.

The bathroom matters just as much. Weak water pressure or water that suddenly turns cold in the middle of a shower can affect a guest's experience more than a missing appliance.

And, of course, Wi-Fi, especially for guests staying longer than a weekend. They check it from the bedroom, not next to the router.

None of these things are expensive. But these small details are what make the difference between an apartment that looks good in photos and one that guests are happy to recommend to others.