Selecting control points (whether Orca3D control points, or the standard Rhino control points), is normally done by simply clicking on the point. This method is usually very effective, but what happens when control points are stacked on top of one another, or are very close? How do you make sure that you've selected the correct control point?
Rhino has a set of functions that make this very easy, by allowing you to select a control point, and then select the next or previous control point in either the U or V direction. These functions are located on the Select Points toolbar, which can be enabled using Toolbar Layout in the Tools menu. For example, in the image above, selecting NextV will select the point on the same column, at the sheerline. NextU will select the next point forward on the same row. There are also "add" versions of these functions, so for example you can add the NextU to your current selection.
If you have multiple points that are stacked, start by selecting a control point that is outside of the stack, on the side next to the control point that you want. Then just "step into" the stacked points with NextU, NextV, PrevU, or PrevV to get the control point that you want.