After a meeting, do a prompt followup. Put some emotions into it (Why was it nice to meet him?) Do it within 12-24 hours.
Expressions of appreciation, heartfelt emails, etc are more valuable than monetary gifts.
Following up is critical!
After the follow-up email, connect on LinkedIn. Put the person in a contact list, and put a reminder to reconnect in a month. Also, try to get an email commitment to meet again (e.g. “when next in town?”). Then use that email when the opportunity arises. When you do re-meet, focus on what you can do for them - not the other way round.
Also, send curated, relevant articles to the person occasionally - but not a mass email.
In followups:
- Express gratitude
- Include an item of interest from the meeting (could be a joke)
- Reaffirm commitments
- Be brief
Appreciate any people who were go-betweens as well (cc them)
Handwritten notes are great, but emails are fine.