Cleaning.
As in, actually, get your gloves on and deep clean. How does the outside of your building look? Is it simply a matter of sweeping up debris and washing the windows, or do you need to pressure wash the exterior, repair the roof, or touch up any paint? Do you have equipment lying around here and there, or is everything put away in a clear and orderly fashion?
This applies to the inside as well. The lobby/reception area is the first impression a customer has when they visit your business. If your lobby is unorganized and cluttered, that is the first image that your customers have of you. Some light cleaning, decluttering, a fresh coat of paint, and open curtains will go a long way.
Take a walk around the grounds and imagine how it would look from a customer’s perspective. If you aren’t satisfied with that image, you need to make a change.