To start with it's best to look at the individual needs of each persons chart and how they relate and what they are looking for. Astro.com does have an option composite + natal midpoint method (2) which I find helpful. If you choose to post the synastry bi wheel from astro could you please select the 2nd synastry option as it will put the houses and degrees onto the wheel which is far better for us to evaluate matters....
If you post the synastry chart and realise it doesn’t show the degrees (which we need to look at) you can find the degrees and other information in a separate PDF on the synastry page of astro.com. Look for the link "View the additional tables (PDF)" and click on it to see the additional information. Reading a synastry chart is mainly about reading the aspects between the planets in the two charts. So once you find the PDF, scroll down to the bottom of the page and look in the synastry grid that is there. Unfortunately, you can only see/read these and not save/upload. That’s why I like to see both natal’s and composite. This grid (in my opinion) has too many minor aspects and the orbs are quite wide. I like to use + - max 3’

When looking at a woman’s chart the type of man she would look for is her sun sign and mars traits, plus 7th house planets and house cusp ruler and where that ruler was deposited.
When looking at a mans chart for the type of woman he would look for is his venus and moon sign and then 7th house planets and house cusp ruler and where that ruler was deposited.

Although synastry is a valuable tool with astrology it cannot 'make things happen' even if you have the best synastry in the world unfortunately.

In synastry I use tight orbs and view aspects between one person's outer planets to the other person's inner planets as being "karmic connections"......usually with the outer planet person doing the teaching and the inner planet person doing the learning.

If you want to research more into synastry try here
http://cafeastrology.com/astrology_of_relationships.html
http://www.cafeastrology.com/synastry/interchartaspects.html
http://www.cafeastrology.com/synastry_house_overlays.html
http://www.astrology-numerology.com/synastry.html
http://www.astrology-numerology.com/synastry-houses.html
http://www.astrology-numerology.com/synastryaspects.html
http://www.cosmitec-astrological-compatibility-advice.com/astrology-marriage.html
http://www.astrologyweekly.com/forum/showthread.php?t=17513
http://www.astrotheme.com/synastry_advice.php
http://www.astrology-x-files.com/synastry/ascendant.html


relationship sticky
http://www.astrologyweekly.com/forum/showthread.php?t=28945
http://www.astrologyweekly.com/forum/showpost.php?p=254409&postcount=9


Unfortunately, there is no set formula or signature for marriage or childbirth, although others may disagree, apparently horary and vedic seem confident in this area. There are indicators and potential as there would be with natal, solar return chart but guarantees -- (post 2 & 3 below)
http://www.astrologyweekly.com/forum/showthread.php?p=207744#post207744