Click on an axis to select it. Knobs appear on both ends. Move the mouse over the right knob of the X-axis or the top knob of the Y-axis. Drag the axis to make it longer or shorter. Or grab the middle of the axis and move the entire graph around the page.
Move the mouse over a symbol, title, axis, etc, and right click (control click with Macs). The shortcut menu will give you many choices to format the object.
Change Graph Type dialog
You can bring back the Change Graph Type dialog (the same one you used to create the graph) any time. This is useful for making large changes in how the graph looks.
Format Graph dialog
Use the Format Graph dialog to change symbols, bars, error bars, area fills, legends, etc. Double click anywhere on the graph (except the axes) to bring it up. Be sure to look at all the tabs.
Format Axes Dialog
Use the Format Axes dialog to change the range, interval, scale, numbering, etc. of the axes. Double-click on an axis to bring it up. Be sure to look at all the tabs.
Select a range of points on a data table, and change how corresponding points are graphed
Select a cell or a block of cells, right (control) click, and choose Format Points. You'll be able to change the color, size, symbol, border, etc. of the points or bars that correspond to the selected cells.
Choose a color scheme to change all colors at once.
Magic -- Make Graphs Consistent
The Prism Magic tool makes one (or more) graph look like another. It is a huge time saver.