Quote Originally Posted by velogirl
It sounds to me that when you're on the small ring, you need to trim as you get to the smaller cogs on the cassette. The nice thing with a 10-speed double is that you can get away without doing this most of the time. However, if you don't trim on the small ring, you will indeed need to shift twice to get the chain to move to the big ring.
profŕvélo, are you shifting through 2 clicks to get from the small to the large ring, or are you getting the shift with one click and then having to trim? If the former, you need to follow VG's advice. Assuming your rear derailleur is on a middle or outside cog before you shift the front, your front derailleur should already be trimmed out one stop to be properly centered in the small front ring. If the latter, you should not need to trim if the rear derailleur is on an outer cog. If you do, then the outer stop of the FD is set wrong.