How to know is this partner really good for youRemember the happiest day of your life- try to feel happiness, joy, etc.
After you feel all of this try to imagine your partner or person you want for partner with you in this happiness and see how it's feel.
If happiness decrease he\she is not as good partner for you..
Also this meditation can be used to see if new work\house is good for you.
Any situation could be tested with this technique.