I'm coming from (a long time ago) 3dsMax. It had this really handy ability to provide transform helpers and you could select parts of them. For example the translate helper was an XYZ "cross" with colors, and you could click and drag the XY plane for example to constrain movement there.
I've noticed that blender doesn't have these, so moving edges about when preparing to extrude can be quite difficult, is there a better way?