Make it the active style in your template.
I changed things in the styles manager so that when I use a particular type of dimension (Baselin, Ordinate, Chain, etc.) I now get the dimension style that I desire. What I can't seem to find is what controls the dimension style that is activated when you just use the general dimension button. I still get the "by standard" inventor default. I would like to have this button activate one of my dimension styles.
Sounds like you were on the right track in the Style & Standard editor, you just didn't change enough.
Check your Object Default settings for the following:
These are the ones that are created by the General Dimension command, so changing them to your desired default style should get you what you want.