Here are a few things that help show my clients that we are professionals. Call people back within a few hours, definitely the same day. Matching marketing materials. Everything has the business logo on it, and keeps with the same color theme. My online presence also gives my practice a professional look. I keep my business page separate from my personal page on Facebook. I have online scheduling available, and a website. In person, everyone that works for me must be dressed professionally. That means; clean appearance, black pants and a clean top. No designs or writing on clothing is allowed unless it is the business name/logo.