Acknowledgement, appreciation and gratitude form the essence of thank you letters. A thank you letter conveys to every giver that their gesture has not gone unnoticed. Timing is important, so make sure you pen this letter as soon as possible.
It is best to send out handwritten thank you letters. In case this is not possible, use personalized stationery and include a handwritten line or two at the end.
While writing a thank you letter remember to keep it short and sincere. Acknowledge the gesture by mentioning about it specifically. It could have been a gift, a cheque for a charity or a birthday present. This will reassure the reader that you mean what you say and that it is not a general letter.
The letter can also mention how much the gesture has meant to you or how it has made a difference to you. Do not use flowery language and exaggerated praise while thanking. It can sound phony. Your sincerity should shine in your simplicity.