Well, well, well
While magic is common, resources are rare and once your own powers are depleted, there are very few things you can do about it, besides good old rest and relaxation. But many mages do not have the patience for that.Let me introduce you to the well, ritual.
The tripple well ritual is aimed at replenishing your magic power before it renders you completely "docile", as other practicioners of the craft would call it. The hardest part of it is to not know your limits precisely, but to catch yourself just before you reach them. Most magically talented people only realise way too late that they cannot utter a spell more.
Should you train your resilience to look for the signs, you might be able to eventually learn the well ritual. Three bodies of water are needed to perform it. First well is you, the magician, second well is a renewable magical resource (moon, stars, sun) and the third well is usually a body of water, usually a bath, but some say even a bucket is fine.There are even rumours about a wizard successfully pulling this ritual of with a single can of energy drink. But this might be just a college rumour. Rubber ducky is purely optional.
Once you have your three wells, you can perform the syphoning. And we do speak of performing quite literally as music is necessary to lure the magic power from one vessel into another. Most magic users needers do just fine with humming a single tune and watch the magic flow back. It can take you a while to find your voice and what frequency is necessary as this is individual to the individual and the type of magic power they need.
All that is left is to concentrate and don't let the magic escape away from you. This can take anywhere from ten minutes to a full hour. Enjoy the bath.