Connect email, calendar and phone so your database fills and updates itself, then merge duplicates on email address.
The idea
A database you fill and update by hand dies the day you stop. Most of what you need already lives in your email, calendar and phone, so let software pull it in and keep it current. You end up with a running record of every email, meeting, call and text at almost no effort, and your manual time goes to what software can't capture.
How to do it
Connect your email (Gmail, Office 365, or anything with IMAP). Quick win: start with your work email today.
Connect your calendar, so you know when and where you met people.
Import your phone's address book.
Export what won't connect (LinkedIn gives you a CSV) and import it. Repeat as part of a regular cleanup.
Merge duplicates on a unique identifier, ideally email address. If you know one John Smith, his work and Gmail addresses shouldn't be two contacts.
Add enrichment, like job titles and social profiles, if your tool offers it.
Example
For one of my teenage birthdays I got four copies of Green Day's Dookie. I loved that album, but I didn't need four of them on the shelf. Automated imports do the same thing to your contacts. A good tool spots the copies, matched on email address, and reconciles them.
Watch out for
One-time imports. The first time someone changes their email address, a snapshot stops matching reality. Set up continuous syncing.
Walled gardens. Facebook and WhatsApp let almost nothing out, so those relationships need manual entry.
CAPITAL: Aggregate: Build one database you own with everyone you know, fed automatically from email, calendar and phone, as the base for everything else.
Include Everyone: Put everyone in your database, personal relationships too, and prioritize afterward instead of filtering at the door.
Own Your Own Database: Your relationships outlast any employer or platform, so keep your own database, export backups, and check the exit door before adopting a tool.
The Will I Use It Test: Pick whatever relationship database you'll actually use, from spreadsheet to CRM to whiteboard, and drop anything you don't.