Thomas gave me this advice several months ago, and it made my life as a consultant less stressful and more lucrative. It worked particularly well with a menu proposal: here are three different engagement lengths with expected project details for what we can accomplish, which one works best? Instead of them quibbling about my rate, they just said "The difference between B and C doesn't matter too much to us, so we'll drop the last week and pay you the B rate. Cool?". Worked perfectly for both sides, and I got a week with family.