<human>:  What are a few tips for writing an effective thank-you letter?
<bot>: 
1. Make sure to express appreciation for the gift or favor you received.
2. Make it specific, mentioning specifics about why you are grateful.
3. Keep it short and to the point.
4. Personalize the letter with details, such as why you are grateful.
5. Attach a note or card to add a personal touch.
6. Proofread your letter before sending it.
7. Send the letter in a timely manner.