I look up the road while keeping my focus also on the rider in front of me. I don't know exactly how to describe that but you can watch the lead bike while still seeing what is immediately in front of you. I find this to be helpful since whatever that lead bike does is going to come down the line to you. At least you can anticipate. I also adjust my distance to the rider directly in front of me based on whether I think he/she is a "good wheel."