Unless I'm riding very hilly terrain, I don't like the 50/34 combination. I usually run 50/36 and find it keeps me on the small ring more on uphill sections and on the large ring for flat or downhill sections.

When I stop at lights, I usually shift down a full stroke of the lever (3 cogs) and leave it on whatever ring it's on. If the start is uphill, I might make an effort to drop onto the little ring.