Creating a circuit can help create a shift in your energy or mindset. This particular technique is one I use when finding it difficult to shift negative thinking, or feeling overly sluggish or unproductive.
Working with your crystals is a personal and individual thing, and very much comes down to the crystal itself too. I've had crystals I've programmed (set intentions for) with great success, and some I've just let do their thing which has resulted in incredible experiences too.
I have crystals with me all the time! Black Tourmaline in my car or handbag for protection, Aquamarine next to me while I’m writing, and Citrine with me when I’m working on business growth. Here are some examples of crystals by purpose, its not limited to these crystals alone, but these are the ones I find myself recommending time and time again.