Tips for offset axes:

Prism makes it easy to create graphs with the X and Y axes offset from one another. This can make a graph easier to read when there are values that would be close to an axis.How to offset the axes

It is a setting in the first tab of Format Axes, under frame style. 

How to adjust the size of the offset

Select the axis, then drag left end of an X axis or the lower end of the Y axis and drag them to adjust the spacing. Dragging the right or upper end of the axis segment will change the size of the offset, not is position.

If your graph is too close to the left side or the bottom of the page, however, you might not be able to drag the end of an axis. The solution is to make your graph a bit smaller and move it away from the edge. Then you'll be able to drag the end of the axis to where you want it.

Tips for  having offsets with graphs that have both right and left axes

To bypass a bug in Prism, first create the right Y axis (so the graph has both axes), and then specify that you want offset axes. That will work. If you first specify the offset and then specify the right axis, the offset on the right side won't be quite right. It will be offset to the right, but not up (you can select, then drag it up). Fixed in 6.03 and 6.0d.