Also on clothing--Do NOT dress in a suit. Depending upon where you are.. Dressing in a suit only makes most clients feel uncomfortable. Of course if you are marching into a building sky high in front of a board discussing you and your services--by all means wear a suit. But if you are dealing with a normal client dress business casual.

A nice colored shirt with a matching tie will go over well. Casual dress shoes and a nice pair of dress pants.(Never cargos, those are for young computer repair casual. )

Always have a pen and something to write on. It's very awkward when you are asked to do something and you need to write it down but must ask for paper.

A good form is also to ensure if you have any tatoos or visual peircing that they are not visual to the client. Speak clearly and directly. Don't overexaggerate at all. Clients have a tendancy to hear things and remember them and hold you to them.