You've made the
first "cut" about your preferred and less preferred kinds of sustainers. Now
it may be helpful to consider some specific possibilities. Feel free to make
notes to yourself about any of the following which catch your attention for
whatever the reason (e.g., Hmmm, never thought of that one before; What does
that mean? Ah, this could work at the times when I _____; This one might be
worth looking into.).