If you attend a few conferences or events each year, you’ll meet interesting people that you can follow online. Often there will be a conference Slack group where everyone attending can chat. A link and instructions to join this group are typically provided in an email after event registration, generally weeks before an event is slated to start. Join it. Add folks to Twitter that you’re looking forward to meeting or you’ve had interesting conversations with. If you’re at a larger event, temporarily add it directly to your name on Twitter.
For example, if your Twitter name is normally “Alfred Lin,” change it to “Alfred Lin at Cool Eng Event Dec 6-10” so people know you’re going. You might also temporarily pin a tweet to your profile about being there.