It’s a new Moon today, starting from 2:18am GMT. Based on my scarce knowledge, I think it’s astrologer Jan Spiller who popularise the idea of making wishes on New Moon. The idea is to write up to 10 wishes on paper on days of New Moon so that they magically come true.
You can wish for anything as it’s a wish after all. However, a practice is align the nature of the wishes to the zodiac sign of the new Moon. For example, the new Moon today is in Capricorn. So, wishes relating to Capricornian themes such as achievement, ambition, perseverance and determination may be ideal.
Making wishes relating to the zodiac sign of the new Moon is fine. But surely we could go deeper? How about we look at the house that the new Moon falls into? For instance, the new Moon in Capricorn today falls in your 8th astrological house of transformations, shared resources, deep emotions and intimacy. So, it may make sense to make wishes relating to say, deeper intimacy with your partner or even getting that new mortgage loan (which falls under the 8th house).
If we really want to, we can go even deeper. We see whether the new Moon makes any direct contact with planets and angles in your birth chart. For example, the new Moon today is in 26° 54′ Capricorn. It directly contacts your Venus which is in 27° Capricorn and in the 8th house. If that’s the case, you could consider making wishes on greater intimacy in your relationship or being more charming and popular when you meet the loan officer for that mortgage application of yours.
Now, go make some wishes!