Steve,
If your Form Tool sketch is dimensioned to the model with external references for placement you'll need to delete them to allow you to modify the sketch orientation which can be done using the following.
Tools > Sketch Tools > Modif
y...
If you have exteernal relations you'll see an error message
Tipically these are placement or colinear coincident relations. Display/Delete relations External will show what these relations are.
When Modify Sketch is active you can use Left Mouse to move translate the sketch around or Right Mouse + Drag to rotate the sketch around it's origin. You'll get lower increments the further out you move the mouse from the rotation point Snapping at 90,45,15,10,1 degree rotations.
You'll see three white dots on the sketch origin X axis and Y axis which will modify sketch as shown in attached image.
Right Clicking the dot on the X or Y axis will flip the direction without needing a mirror command. and the Center dot at origin will flip X and Y which is the same as Rotating 180deg. I always try to set the sketch the way I'd like it to be orienting when first creating it. The Modify Sketch is only available if you have at least one entity and no external relations. Typically I sketch a point and set it's location to 0,0 in the property manager.
Michael