Accurate width and height measurements, along with any obstructions such as sockets, light switches or nearby doors, give a supplier the foundation they need to propose a realistic size. Photos of the wall and its surroundings help fill in details that measurements alone can miss, particularly around uneven surfaces or awkward corners. Where possible, noting how the room is currently used also helps a supplier understand any practical constraints that might affect the final specification. Taking photos from a couple of different angles, rather than a single straight-on shot, tends to give a supplier a clearer sense of depth and any subtle irregularities in the wall. If the wall has been altered recently, such as new sockets added or a wall repositioned, mentioning this avoids working from outdated assumptions. A brief note on lighting conditions in the room can also be useful, since this occasionally influences finish recommendations.