An open loop is an intention that hasn't been completed or closed. Each intention we form, whether large or small, requires creative energy. Open loops require energy to sustain them and therefore siphon off our creative, manifesting power.
An open loop could be a book you meant to read, or a putting off a making the phone call for a relationship you would like to heal, or a car you dream of buying, or a place you intend to visit. The list can be extensive when you give yourself the time to acknowledge the open loops you have created.
So, how do you close a loop? Through intention. Halfway through a book you don't feel you will complete? Cut the cord for yourself with an intentional statement that you are complete. Intention can also look like making the phone call to begin repairing that damaged relationship. Or allowing yourself to go on your dream vacation.
Open loops are evidence of our creative, manifesting power. Managing them responsibly looks very much like pruning a tree. You release the unimportant loops to give strength to the that which you would most like to manifest.