Most first viewings are wasted, and not because the property was wrong. They are wasted because nobody decided in advance what the visit was supposed to answer.
Here is the short version: arrive with three questions you cannot answer from the listing, and leave when you have answered them.
Bring a number, not a feeling
Know the monthly figure you are comfortable with before you walk in not the maximum a lender will allow. The gap between those two numbers is where regret lives.
If financing is not arranged yet, that is fine, but have a written pre-approval position before you make an offer. It changes how a seller reads you.
Look at the things photographs cannot show
Noise at the time of day you will actually be home. Water pressure. Where the light is at 4pm in winter. Whether the parking is real or theoretical.
Open a window. Run a tap. Stand still for a minute and listen that minute tells you more than the second bedroom does.
Write it down before you get in the car
Three properties blur into one by Sunday evening. Two lines each, written on the doorstep, will still be legible in a week.