Observe the property without jumping to conclusions
Look at the room layout, light, storage and visible condition. Take notes, and photos only with the required permission.
A visual visit does not confirm the condition of components. Note the items to have examined by a home inspector or other professional.
Ask the useful questions
Ask which documents are available on work done, maintenance, systems and inclusions. For a condo, also ask about the fees and management documents.
Check the information against the appropriate documents; a verbal answer does not replace a professional check.
Look at the area too
Make the trip to transit, shops or the services that matter to you. If possible, visit at different times of day.
After several visits, compare your notes using the same list of criteria rather than relying on memory or love at first sight.