Who would you trade up for, and where would they have to slip to in order for you to do it?

Example: if fournette falls to 14 or lower I'm trading up. If Corey Davis is within a few picks of us, I'd consider that as well. Not sure if I'd trade up for Foster because I feel if he's somehow dropping, he'll drop to 21 regardless. What do you guys think? Just wanted to start a discussion because I literally cannot wait anymore for the draft