I recommend you get yourself a 1 gallon gas can specifically for your bike.
For break-in I run 25:1 (5.2 oz. 2/3 Cup)
Thereafter 32:1 (4 oz 1/2 Cup)
I have a glass kitchen measuring cup for adding oil to the gas can.
Just gas your bike up before you leave home and when it's empty fill it back up and mix again.
The point is trying to mix it in the tank is not a good idea and too much oil just clogs your exhaust pipe up and drips oil.
Also note there are synthetic oils like Opti you can mix up to 100:1 that still lube your engine but they are expensive.
On the other hand, the less oil in with the fuel the better as oil doesn't combust.