This is how you can do it step-by-step:

• Click on the name of any commenter on your post that is new and looks cool to you and go to their profile.
• Go to their recent posts and see if you like their content. If you do, leave a thoughtful comment.
• Click back to their profile and then hit the “more” button.
• Then hit connect. Feel free to add a quick note or not. It’s best to split-test both to see what gets you the most accepted requests.

(Make your note interesting and don’t be afraid to add some wit, and humour or give a thoughtful, relevant compliment on their content or profile.)