One idea is to have the shift or ctrl keys temporarily toggle "snap to
pin" mode. Draw nets as usual, but just before you select the final
pin, press and hold the shift key to go to snap to pin mode, select
the final pin, then release the shift key to revert to grid (or no
grid) mode.
This is an interesting idea. I seem to remember some general drawing
package years ago (Micrografx Designer, maybe?) which, when drawing a
line, would force it to perfectly vertical or horizontal if you dragged
the second endpoint while holding down one of the modifier keys. This
seemed very streamlined and supported the "one hand on the keyboard,
the other on the mouse" way of doing things.