IME, most alkaloids get into the tea after you steep & strain 2 times, the third one should be enough to ensure there's practically nothing active left within the fungi. So if you make 3 pulls, you shouldn't need any more mushrooms to start.
EDIT: You might be aware of this already, but I thought I'd mention it just in case. Some of the active alkaloids are somewhat heat sensitive (I forgot which it was, psilocybin or psilocin), so don't put the mushrooms in boiling water, let it cool down just a bit first (about 70 degrees celsius should be the appropriate temperature). Also, adding some lemon before you insert the shrooms is a good idea as it acidifies the water, which helps with the extraction process. Lemon also helps with the taste, and feel free to add some regular tea and sugar or honey as well to maximize enjoyment %)
And yes, adding some ginger into the mix can never hurt.
EDIT2: Another suggestion - if you're making tea from high dose of mushrooms, it might not be a good idea to start the drinking with the first cup as it contains the most alkaloids, and you might not be able to finish drinking cup 2 & 3 before you're catapulted into another dimension. Drink the cups in reverse order instead (starting with the last and finishing with the first).