Well, Synchronous aspects make good friends but never good couples. Ít best if there are a lot of COMPLIMENTING ASPECTS in couple’s charts rather than synchronous.
Friendship is short term, marriage (if that’s what you are looking for) is very very long term. There will a a lot of lot of Friends who will come and go in your life. But only 1 spouse (I am a monogamist :))
Planets should never be 6:8/2:12 positions (super impose the 2 horoscopes – ie make a new horoscope to see how will your planets and his/her planets be places if all are displayed in the same chart – start from one planet and move clockwise till you reach the same planet in his/her horoscope) to each other in a couple’s chart. If this happens, this positioning will cause havoc in that aspect of their lives.
So for example
6:8 Position – if Sun is i Leo for you, it will create a 6:8 position if Sun is in Capricorn in you friend/spouse’s horoscope.
2:12 position – If Sun is in Leo for you and in Virgo in your friend/spouse’s horoscope.
This applies for all planets and even ascendants/Lagna.
The more you avoid 6:8/2:12 positions, the lesser the misery.