I use LinkedIn. I'm not a tech guy and work in tax. Whenever I meet clients, I add them on LinkedIn and leverage that to find more introductions. I know LinkedIn isn't well liked in the tech space, but for global businesses doing infrastructure development, it works exceedingly well.

For relationship management, I try to meet at least 6 clients face-to-face every week.

What specifically about LinkedIn makes it a disaster in your eyes? I've recently started using it again and found it to be immensely helpful.

Despite its unpopularity on HN, I find LinkedIn to be excellent for my needs.