You have established contact with the customer by saying Hello. When you then ask if they need any help do not be put off if they say no and that they are just looking. Just smile and give them space. You will be surprised at the number of people who having refused your help in the first instance, once they are given space will return to you and ask for your help.
They don’t feel under pressure to buy something which has the reverse effect, they then usually want to buy something. Often customers do not want to be hasselled when browsing in a shop, if they really need advice or they look like they are looking for help, then you should approach.
Even giving help it is a good idea not to push but to let the decision be theirs. Once you have made the sale it is then a good idea to make small talk about the product and let the customer know that you can always get it for them if it isn’t in stock. Remember to thank them for their purchase.
This gives the customer a complete experience and the next time they are perhaps looking for cosmetics or toiletries they will remember what it was like in your store. They will think of the atmosphere, the lighting and temperature. They will remember you helping them to select their purchase and they will remember the way they felt leaving your store. It is the way they felt leaving your store that will bring them back in again and again.