When you’re trying to schedule a meeting with someone, make it easier for them to respond by proposing one or two choices in your initial email: “How about 9:00 AM on Tuesday?” or “Are you available on Tuesday at 10:00 AM or on Wednesday at 3:00 PM?”
Don’t give them many options (“any time next week”) or, worse yet, don’t ask them to leaf through their calendar and suggest a time (“I know you’re busy. Let me know when you want to meet.”)
Keeping it brief and specific maximizes the chance that one of your suggested times will work out, and they’ll quickly say “yes” without further iteration.