The question can also be parsed into a cluster of overlapping prompts, some of which transition into general efficiency:

• Learn how to do a single task faster.

Ex: Touch typing. Keyboard shortcuts. Find a shorter path. Automate bills. Use a flashcard program like anki.

• Figure out how to do a task less frequently (minimize "in-between" time, set-up and tear-down time).

Ex: Learn what items you can buy in bulk. Cook in larger quantities. Schedule errands together.

• Identity something you can stop doing, or do significantly less of at modest cost.

Ex: Procrastination? Apply the 80/20 heuristic? This category is probably quite personal.

• Learn how to better schedule or overlap tasks.

Ex: Learn to cook multiple things at once. Learning to schedule errands at low-traffic time. Listen to an audiobook, or call a friend, or practice singing, etc. while doing mentally undemanding things like chores.