I'm flying TWA from LGA-STL-SFO on a Monday and the same route back that Thursday.I'm flying on a free voucher I got from being bumped off LAX-JFK flightI would love to get bumped coming back.Does anyone have any tips or stratagies that can help?(i.e.-how to see how booked a flight is;when to voulanteer;what to ask for in compensation-voucher,ff miles or otherwise)