After doing way too many draft simulations, it sure seems like trading down is always a good option. Basically accumulate as many picks as possible from the pick 45-115 range or so. Would I rather have Michael Mayer or get Luke Musgrove AND Zach Kuntz? Brian Branch or Antonio Johnson AND Nick Herbig? Jordan Addison or Tyler Scott AND Cedric Tillman?
Unless the staff has a super high grade on a guy (top 5) and he falls in their lap at 15, trade down.