Small round wire sieve that fits on top of a mug, < $20 at the supermarket. I'd bought various devices intended as tea strainers before, but they were hard to clean and didn't let the leaves drain properly. A small thing, but it's meant a lot less irritation.
I've used one of these daily for 5+ years. You, or others, may like it too :) It's a metal basket perfectly sized to fit in a medium-sized mug, to make loose-leaf tea one cup at a time.
