Are there any herbs that have to do with motivation, in terms of their metaphysical use?

many, most are are stimulants. Try making a tea of Yerba Mate, lemon & honey to taste, then ice it...omg it is soo tasty, better than coffee! Many of the herbs in metabolife are also effective in motivation. I find if I take just one, I get twice as much work done if i take none. Ephedra or mormon tea, also very motivating! Just ask those teenage missionaries! Any of the above mentioned herbs can be dangerous if overdose occurs. Just take it easy on the stuff and learn how much it takes to stimulate you. Motivation can be imbued upon the any of the dried herbs or even herbal pills, and can be "charged" by either a chant or simple blessing. If this is done a ritual-religous context where dieties are invoked, be sure to offer some of the herb to the diety at the close of ritual.