What about astrological midpoints? I like 'em and I use 'em.

An astrological midpoint is a sensitive point on the zodiacal circle that is midway between two other points.

There is a short distance midpoint that is the most often used midpoint. And there is also a long distance (not to be confused with MCI or AT&T) midpoint. The long distance midpoint generally gets ignored a lot (but probably shouldn't). Together they make up a midpoint axis.....

I pay the most attention to the planetary pictures called direct midpoints. A direct midpoint is occurs when one planet (or other point) is located halfway between two other planets (or other points)

The formula is A + B - C = C.

Here's a diagram for those of us who are algebra impaired.
In this case -- Mars is located midway between Venus and Pluto, so the energies of Venus, Mars and Pluto are all combined on that point.

At the top of the diagram is the short distance midpoint. Mars is located on the Venus/Pluto short distance midpoint. At the bottom of the diagram is the long distance midpoint.

Suggested reading:

"The Combination of Stellar Influences" (CSI) a "must have" for learning how to look at midpoints and other multiple energy combinations. Cosmobiologists and Uranians use this book religiously for assistance in the interpretation of midpoints.
by Reinhold Ebertin
(Buy it now at Amazon.com)

"Horoscope Symbols" by Rob Hand (This book is a wealth of information on all sorts of subjects regarding astrology)
(Buy it now at Amazon.com)

"Midpoints" by Michael Munkasey
(a much mellower version of CSI)
(Buy it now at Amazon.com)

Also see "Going to the Chapel" for the Sun/Moon midpoint.