if a customer hangs around looking over my shoulder I stop working and just chat with him/if he wants to know how long it will take I tell him a lot less time if you are not in my way you choose you are paying by the hour and we can talk all day this usually gets the message across all customers are different.you sometimes need to alter this slightly depending on customer as I am retired now after 30 yrs.in all aspects of the business give it a try