When I was commuting to work I would sprint away from the stoplights in the big ring. I wouldn't cross chain, but I wouldn't be down in the 11 either. So it wouldn't be terribly difficult. I would sprint in the same gear up to a cadence of 120-140 which would get me up to around 22-26 mph. Then I would sit and shift into a smaller rear cog to continue cruising around 21-23, but with a more sustainable cadence.

What I found was cool was that by stressing my legs from the start it would make the large gears feel easier than if I had slowly gained speed and shifted through the gears. It was a mental thing that helped gain some speed. The pain/stress didn't seem so bad compared to what I had just put myself through.