We can 'Bid via Preferences' which allows us to weigh different options and score it. Lazy people dont even look at the lines and do this via a Standing Bid. Myself, I look thru and find 20 or so lines I like and make sure they are on top (Look for commutability, no day trips, overnights at home). To answer you question directly I probably spend an hour or so on it. For March I spent 45 minutes, then the next day looked over my work (Since its a vacation month) and submitted it. Results come out tomorrow.