Look, I'll be honest, you need to weigh your coffee beans every time if you want the perfect brew.
The thing is, I recently got into the habit of using a coffee scoop, and I would weigh each measure before grinding (NO, YOU'RE A GEEK!!) and well, the consistency was amazing. I got the same measure, each and every time. 16g. Perfect for one coffee.
And now, the coffee scoop has a clip that you can use to seal your coffee bag with, and, quite frankly, it's a game changer for me when we go camping. No coffee canister? No scales? No problem!