And if an eyedropper isn't handy you can always dip a (hopefully clean) finger in water and add a drop at a time that way!
I think half the fun of higher proof stuff is tasting them at different proofs. Get an eye dropper or a kids medicine syringe at the drug store. There's a proof calculator on this website and there are plenty of applications out there to help. Typically I will try at full strength, then I like to compare it at 107, 100, and sometimes 90. You'll eventually find a sweet spot or just decide that full throttle is the way to go. GTS is awesome stuff, but at roughly 72 percent it is a beast, even down at 100 proof it has great mouth feel and layers of complexity. Besides, by adding water you essentially get more out of your bottle. There is no right or wrong way, only your personal way.
i will say a syringe or eye dropper with measurements will help you track your expiramentation.
For me, water / ice is virtually never added. Maybe a few drops of H2O but not often. Like Sky, I too drink at bottle proof as that is where the flavor is generally at its best.
I never add Ice. Ice, to me just makes anything of substantial proof taste like cold ethanol. I never got the ice thing.
I rarely add water. I do the small sip/saliva thing with GTS etc.
And I must be the odd man out because I do not like really spicy food. Smokey foods? Yes! I grill steaks over an oak fire and dice them up to use in my chili. But keep your habinerios (sp) out of my chili and the ice out of everything but the occasional Jameson's
Fact of the matter is there is no right or wrong answer to the original query,drink the whisk(e)y at what ever proof suits your own personal tastes.I personally drink everything at proof or with very little water added.I recommend getting a graduated cylinder and use the proof calculator and slowly accustom yourself to higher proofs gradually over time if you are inclined to do so.
8 drops of water per ounce of whiskey used to be my magic ration for just about everything, but when I started drinking more I got lazy and decided I didn't need it. BTW, if I were designing a perfect bourbon for myself, the proof would be in the 90 - 105 range. It's not that there aren't 130*s I don't like, but it's outside my sweet spot.
I tend not to use water or ice, either. I just take smaller sips and roll it around longer as was previously posted. I will on occasion add a few drops of room temperature water but this is more a function of seeing if it will "open up" any flavors from a whiskey that I haven't tried before.
I almost always enjoy my bourbon neat even the 140+ GTS. That said, the first PHC over cracked ice is wonderful.