Heat water, min and a half in the microwave. Add bag for 5ish mins, with 2ish tsps of honey, if you like honey.
Don't leave the bag in there. If you're the kinda person who prefers stronger tastes, you can add a second bag. Longer brewing makes it bitter, not stronger :3
Just saw your post about 100% water changes, but decide to post you a visitor message because i don't want to destruct OP from the last post .
It is completely fine to do 100% water changes. Many people on this forum , even most knowledgeable ones do full water changes. I do full water changes and my bettas live long lives. There is a lot of posts on this forum that i kept actually, so i can show other people when they attacking me about it. Those posts that i kept from people who doing 100% water changes and bettas live long lives. There are a few post that are amazing,when betta got from very sick looking to healthy with daily water changes and good food. Filters are not a necessity for a betta at all. I guess every one has own method to care about our loved bettas:)