It's no rocket science at all
The only thing is that you wan't the substances to be extracted from the leafs,
wether you make yourself a strong solution that you can mix in before usage or make larger ready to use portion you keep in you're storage containers doesn't matter that much.
Personally i find the strong solution more handy, you can keep it in bottles with the cap on, it;s just that i think this way the substances are preserved better then in an aerated storage container.
You can easily dose the way you like and use the rest at a later time.
When you do it at a container a time, you always have to plan it up front