I would say that looseleaf green tea would be a big step up from teabags. A strainer basket that goes in a mug is a very low-fuss way to make looseleaf tea, as they are easy to clean and reusable. Looseleaf Japanese sencha was a game-changer for what I thought green tea could be.

I am personally not a huge fan of the mesh balls as tea tends to escape out from the gap along the middle, and for green tea especially, too much particulate can be bitter.

I also have a teapot with a strainer which functions much the same way, but for when I want to brew more than one cup.