Once again we see the Moon as 3/4 full. Here the fruit drops from the tree or is harvested. It contains within it the seed of the new cycle which is coming.
The relationship between the waning gibbous is opposite to that of the waxing gibbous because as the Moon approaches it's darkest point, it's 'decreasing' potency is growing. Thus, as it moves from waning gibbous to waning half to waning crescent, it becomes more powerful in decreasing energies. So, for minor decreasing and banishing rituals, the waning gibbous Moon is more appropriate because not as much lunar decreasing energy is needed for the ritual to be successful.