When you're at a matcha shop or a tea store, ask about the harvest date. Fresh matcha makes a huge difference, especially if you're drinking it iced where the flavor is more exposed.

Ask if they have samples of the same matcha prepared both ways. Some shops will do this if you're buying premium product. That's the best way to see which prep suits your palate.

Also, ask about water hardness. If your tap water is hard, it can make matcha taste flat. A simple filter or using bottled water can fix that, but it's good to know.