Maybe the question will be closed since it's quite informal, however I just try it. Last time I started to suffer from the boundness of the latin alphabet: I need to make the name of the function clear and attractive but there are no so many letters.
For sets the solution comes from great letters, for operators - from using math styles like \mathcal or \mathsf.
Greek letters I usually use for measures/other characteristics of sets. The problem comes only about function, for which I usually just staring hopeless at my keyboard.
Any help/advise is appreciated. Maybe you can also refer me to some articles on common notation. If it helps, I am working with stochastic processes.