Emailed my CV to the PI after seeing the opportunity listed on their website. They emailed back the next morning to do a phone interview. The phone interview went well and we set up an in person interview. I gave a presentation of my research and then 1:1 interview with lab PI and lunch with lab personnel.

I emailed the PI I was interested in working for directly; he wrote back and we met at a conference. We spoke on the phone afterward to ensure that there was mutual interest, and then he flew me out so I could meet the lab members and present my graduate work.