Handwritten or e-mail?
The current trend, perhaps in response to e-mail overload, is handwritten thank you notes on note cards.
Type of note card?
Purchase tasteful and very plain cards:
You can choose from an array of budget options and still have productive communications.
Timing
Send a thank you note following an interview, a networking meeting, a meeting at an event, program or CLE - basically any time you want to make a good impression!
Promptness counts. While there is no specified time limit, you do not want them to have to struggle to recall you. Try to get your note in the mail within days.
Details
Proofread everything. Twice. Then do it again. The one way a thank you can hurt you is if you make a spelling, grammar, name or punctuation error. Check everything!
Important: Do not try to "re-do" or "un-do" anything from the encounter in the thank you. This is not the place to correct that answer you cringed over during the interview. Keep the focus on your gratitude.