Sometimes around this time customers might place one big order, but then don't plan on ordering again for quite some time. This can mean that your profits might take a big dive downhill (especially right after Christmas) so how can you encourage them to place another order?
If a customer has placed a large order with me (usually over $50), one of the things I like to do is to place a 'coupon' with their current order for 10% off their next purchase. I usually make that coupon expire within the next four to six weeks so that they will be inclined to use it straight away.
Often I'll put something like this on it.
"Thank you so much for your order. I appreciate your business and to say thank-you I have enclosed a coupon for 10% off your next order with me. Use it before [date]. Take care and I look forward to talking with you soon, Regards, Tracey"
The coupon looks even more special and 'professional' if you print it out on card instead of paper.
Good luck with your re-orders!