Pencil erasor size dose? Not too sure about that, you can never be sure of the density of the Spice, even form the same pull, I might still have different density spice.

Get a scale so you know exactly how much your smoking.

You also got to let go try and relax you breathing somewhat, maybe do some breathing exersize berore takeoff.

And you also want to try and just let go, nothing bad will come from this.

And remember to smile.