A personalized and specific greeting, hand-written on stationery using cursive and a fine point pen, is Southern Living’s suggestion for writing the best thank you note. Hallmark recommends sending thank you cards within a month of the related event or gift.
A great thank you note begins with a salutation that uses the correct spelling and appropriate title for the recipient of the card. The first sentence should be thank you or an immediate expression of gratitude. Provide specific words that refer to the gift or favor prompting the note, and offer details about how the gift is going to used, displayed or spent in the case of money. Never refer to specific sums of money, and do not exaggerate the attributes of the gift or favor that was received.
Put personality into the greeting by using the same writing tone as you would in person, but be appropriate and concise with language to avoid rambling. Even if much time has passed, it is better to send a late note than no note at all, but begin the letter with an apology and a recognition of its tardiness.
In closing, reference the future, perhaps noting the next time you will be together, or indicating that you hope to see them soon. Restate the thanks before closing, and use a warm salutation that expresses your regards.