For those who aren't familiar with the lunar cycle, the new moon and the full moon are opposite points in this cycle. Between those two points, the moon must wax (grow fuller) and then wane (grow slimmer in appearance until it's no longer visible). This cycle repeats itself about every month.
With those phenomena (advancing and receding) in mind, let's break down these two in-between phases.
When the moon is waxing...
According to the Astrotwins, this is the cosmos' not-so-subtle signal for you to get moving. The moon is progressing toward complete fullness, so it's high time you ask yourself what you're doing to complete your own goals. Are you setting up the right meetings? Are you saving as much money as you said you would? Are you spending enough time with your BFF? Whatever your plans were for this month, make moves to see them through while the moon is waxing — its energy will fuel your actions.
When the moon is waning...
As the moon recedes and approaches its "new" phase once again, it starts to appear smaller. In the same way that the waxing moon encourages you to be more expansive and outgoing in your actions, the waning moon should turn your mind toward downsizing. Psychic and medium Natalie Kuna suggests evaluating old habits and relationships — is it time to leave them behind or perhaps find a new approach? Or, if you've already dealt with the sources of toxicity in your life (nice work!), use this time to recharge and prepare yourself for anything positive that's coming your way.
Of course, every month brings different life events — and you might not need to take advantage of, say, the waxing moon's regenerative influence on a monthly basis. Observing the waxing and waning moon is not a spiritual requirement, but it can be helpful to know when you'll be moving with the lunar current as opposed to against it. Keeping track of the moon's cycle (beyond just watching out for when it's full) will help you do just that.