If you want a master class in customer relations visit Kha Nguyen at his clothing stall.
Kha has a low key service approach where he engages with the customer without being too intrusive. He constantly watches for body language indications that the customer might need some assistance but otherwise let's them go about their browsing. He gets the balance just right - letting the customer browse, but being constantly attentive to their needs.
However his "killer" talent is his ability to laugh with the customer even when things get a little difficult. I was at Kha's stall last weekend and a husband and wife team were browsing with the wife giving Kha a bit of a hard time about pricing. Kha's tactic was to laugh off the customer's unreasonable request and, although I can't remember exactly what he said, I do remember the customer suddenly broadly smiling, obviously enjoying the exchange. Kha was polite, but firm, and above all, friendly and smiling. The sale turned into a two garment purchase and the customers left very happy.
Getting the balance right with customers is not easy. They can be difficult and sometimes rude and demanding. But we can learn from traders like Kha. Give the right level of attention to your customer, be prepared to laugh and engage with them, and difficulties can be turned into sales.