Avoid over-commitment
It takes a few minutes to entangle yourself in commitments that can take years to unwind.
Learn when and how to say "no."
If you're over-committed, say, "I'd really like to take on that task/role, but I'm concerned that with my current commitments, I might not be able to perform the task to the high standards to which I hold myself."
Before you say "yes" to anything, sleep on it.
If you find yourself over-committed, start delegating, cancelling, recusing, and refusing.