Check out any bookshelves, one we viewed had an amazing array of sexual technique books on a dedicated shelf in the bedroom. Seriously the shelf must have been 3 foot long and not one other subject made the selection. Really chintzy middle aged couple too, I gave her the sly old fox wink as we passed in the hallway.
More usefully. Check any obvious flaws in the structure, you don't need to an engineer to spot loose tiles, guttering, poor pointing or brickwork. Any areas of discolouration on or around window frames. On second viewing check neighbours and the wider area, neighbours can make any house a hell hole.
The take lots of photos thing is good, take at least one ofte outside at the start of each visit so that you have a marker of what photos belong to which property.
Have a little vision, if the basic structure is solid then most everything else you'll see in the house will be gone by the time you come to move in.