First of all, you have to know YOURSELF, and what you are good at and what you are not good at. I have found honesty works although of course, I dont push the things I need to improve on. I may tell someone that a particular area (if that is one of the things they are looking for) that I am still experimenting to find the best way to clean something. I will give you an example. White water stains left on glass shower doors are a BIG problem where I live. Its calcium and other minerals in our water. When I see glass shower doors, I start by asking if the stains bother someone. If they say yes, I tell them that I will do my best to remove them, but it wont happen after one cleaning. I tell them I am still trying different products and methods to remove those stains. And that is the truth!
Maintain eye contact and smile frequently. Come across as confidant but NOT cocky. Come across as someone who truly wants to help and be of service. Come across as someone who is honest, reliable, and works as efficiently as possible. These are things customers want to hear. Know your specialties - the things you do best and put those things into this conversation.
These are just some super quick thought. I am still learning, too.