One thing alot of mill operators seem to have problems with, is making workpiece offsets. Some have to look on the machine at the labels (X+, Y+, etc..) and then use their hands to help them try and picture in their mind which way to go... and some still make the wrong change. Some think it matters what type of machine it is (table moves or spindle moves) which I say it doesn't matter.
If you're running part and you have a 1 inch dimension from the left edge of the part to a hole and it checks .990. I look at as the feature (hole, web, etc) needs to move right .010. When you move right on a X,Y graph, that's in the plus(+) direction, so make a plus offset in X workpiece offset. It doesn't matter what type of mill machine you're on.
So, if a feature needs to move right(X+), left(X-), up(Y+), down(Y-), deeper(Z-), and less deep(Z+)
Now I'm confused
Jack