How to fix front gear taking 2 shifts just to move onto next cog I was out on a ride yesterday and several times when I was changing up and down between big chain ring and little chain ring (I only have the 2 rings up front) it required 2 gear changes. The gears actually settled on an imaginary middle cog! How can I fix this?
I think Shimano integrated shifters ("brifters") for the front derailleur on a triple normally have 5 indexed positions: 1-3-5 are the main positions that match the chainrings and 2-4 are intermediate spots to avoid chain rub for some chainring+sprocket combinations.  If you give the front shift lever a short pull it will click once and the front derailleur moves one position.  Give it a full pull and it should click twice, moving two positions.

Normally going up to a bigger ring requires a 2-click upshift;  sometimes you need to give it a one-click downshift afterwards to eliminate chain rub if you're in a larger rear cog.  Going down a ring may only take a 1-click downshift, depending on what position the derailleur is in.  All of this is based on my experience with a triple, but should work the same for a double.

If shifting problems are more noticable going up to a bigger ring (needs more clicks than before) then this is probably due to cable stretch.  If you have a barrel adjuster on the front derailleur cable, try turning it counterclockwise (looking at it from the side where the cable housing enters it) to tension the cable a bit.

If the problem is when dropping down to a smaller ring, then either the cables are sticking somewhere (worn cables/housing) or the front derailleur is sticking (needs lubrication or has a worn spring).