This is personal preference but this is what I do.
I use mostly 2 Seam Fastballs because they have more horizontal movement than the Sinkers. If you look at Brooksbaseball.net, almost all Sinkers have greater horizontal movement than vertical movement. If they have more Vertical movement, I give them a Sinker. Also, when you edit a 2 Seamer, you can get the MPH higher than with a Sinker.
Same thing with Circle-Change. If you look at the numbers, most pitchers have a lot more horizontal movement than Vertical movement on their Change-ups.