Definitely just keep your eyes out on the trail ahead of you. That will help. Especially if you can look 25-30 feet ahead instead of looking right down. I can't believe how much that helps with the fear of immediate obstacles, especially drops and cliffs.

There's a section of trail that I used to ride that I completely did not realize had a huge drop-off until someone pointed it out to me. After that, I was freaked out every time. I had always been so focused on the trail . . .