Here’s a neat little trick that should be obvious (but it wasn’t to me). The new moon is ALWAYS in the same sign as the Sun. Why? Because the new moon is always right next to the Sun.
Now a FULL MOON is always in the OPPOSITE sign of the Sun because it is 180 degrees away from the Sun (in an astrology chart).
If you know what sign the Sun is in, you know what sign the New Moon is in.
If you know the opposite sign, you know where the Full Moon is without looking it up.
Aires is opposite Libra
Taurus is opposite Scorpio
Gemini is opposite Sagittarius
Cancer is opposite Capricorn
Leo is opposite Aquarius
Virgo is opposite Pisces
and then it begins again
Most of us can remember the sign opposite our own, so that only leaves 5 to memorize 🙂