I have that same infuser and use it for single cup steeping! What's nice about that tea strainer is that it has a cover which is important to keep all of those beneficial volatile oils from steaming out. What are the other loose teas you are using?

If you want to make more than a cup at a time, you can put the herbs in a mason jar, let them sit and steep for at least 20 minutes and then just strain the liquid out. Either way works depending on the quantity you want to drink.

You can reuse loose tea but I believe most of the nutrition will be in that first pass.