To customise your habits in Balloon head to the habits tab and click on the icon in the top right:
That will open a menu that will allow you to reorder and enable or disable different habits.
Any time you add a medication type to your account we will automatically create a new habit for that.
We currently don't support creating custom habits, but this is something we want to build in the near future.
If you'd be interested in this feature let us know via the chat, so we can let you know once it's realeased.