For me it's the usual, remembering conversations we've had about their family etc and asking how everything is going- did little johnny enjoy his bday, every now and then giving them the odd treat like maybe a small discount of another treatment, the norm really. Sometimes I'll make a suggestion based on the something theyve told me ages ago, so oh XXX I got this new Shellac shade today and thought it was really you, that sort of thing. I did have a repeat client the other week book in for Shellac fingers and toes on her actual birthday so gave her a complimentary glass of wine and some Thorntons chocs on a plate for when she was having her Shellac toes done. When she booked the appt i asked if she wanted red or white wine or a nice glass of juice. She was really chuffed bless her. In saying that, I don't think its the giving them things that shows clients we care or going out of our way for them, I think it's about remaining professional but making them the centre of attention when you're pampering them and letting them feel completely relaxed in their surroundings.
I'm not really sure if i've actually answered your question, now i read that back lmao! xx