Like chess, the art of engaging a customer on the sales floor starts with the very first act of engagement. Most sales assistants have their own pet phrase, and most of the time their opening move results in failure. By far the worst possible thing your staff may say (first thing) to a customer is:

"Can I help you?"
 
There are practical reasons, psychological reasons and social reasons why this approach is a poor opening move:
 
ONE: Customers hear this so often, they have practised their response and it is likely to be 'no thanks, just browsing.'

TWO: It is a closed-ended question and after their response, there is nowhere to go except to back off. (Less enthusiastic staff know this and love that it means less work for them – or I am I just being cynical?)

THREE: Because it is a closed ended question, you have at best a 50% chance of a positive response. (Customers are hard to find and you would surely like a more than 50% chance of a sale?)

FOUR: The question creates an imbalance in the power-relationship where a customer feels that they have been identified as being 'in need of help' and they interpret that as being targeted as someone that could be 'sold to'. (These are sub-conscious reactions, but they are nevertheless real.)

The only time that this approach works is if the customer is really in a hurry and have been frustrated by the lack of available service. In this case we missed the buying signals and getting a sale out of this situation is attributable to the customer's tenacity and/or l;ack of alternative options and not selling skill. Unfortunately this happens often enough to make people think that 'can I help you' works just fine.

The above opening line is the worst, but is closely followed by:
“Just yell when you need me.”
“Won't be a sec.”
“You all right there…?”
“Just browsing?”
  
I won't elaborate on all of them – let's focus instead on what to do next.
 
The first thing is to actually time your approach properly by reading the approach signals. And secondly, adopting the right body language clusters. Assuming you get that right, a sincere, welcoming smile is quite adequate – especially if you are wearing your badge and/or uniform (effective symbols of authority.)

OR SIMPLY

“Hi or Hello or G'day” – followed by…

“That's a nice…" and say something positive about the merchandise they are handling.”

There are other more advanced techniques, but the hardest part is unlearning the bad habits first.
This infomation was written and sourced from http://www.insideretailing.com.au/ - an excellent source of useful and practical articles all pertaining to Australian Retail News.