A colleague says, “The hardest thing about going up for Full Professor is to get external references. You’ll need several people from other schools who are recognized authorities in your field and who will want to write a narrative about your scholarship. That’s so hard!”
When I was a beginner Assistant Professor, I also found that to be very intimidating. I’m not sociable! I don’t network! I don’t meet people! Nobody knows me!
But now the hardest part of the task for me is to narrow my list to 10 names. There are so many great people to reach out to! You end up knowing people and being known by them without trying. As long as you publish worthwhile stuff, of course.