An important factor to consider when batching cocktails is dilution. A cocktail is shaken or stirred with ice in part to chill it, but also to dilute it. When batching, you can dilute before or after:

• If diluting before, add around 15-20% of the cocktail's volume in filtered water to the batch. For the aforementioned 24 ounce Negroni, I would add about 4 ounces of water to the batch. This is the most convenient option, and it's probably best for cocktails that will be served up, like Manhattans and Martinis.
• Diluting after requires you to simply measure out how many cocktails you're preparing for that round and then shake or stir, and strain. This is a bit less convenient, but still a time saver over having to pour and measure all the ingredients for each cocktail. (For my straight-from-the-freezer Negronis, I typically add a large cube to a rocks glass and pour to about 2/3 full, then I stir for about 15-20 seconds and drop in my orange slice.)
• A third option is to use “shitty ice.” Shitty ice is a term coined by the legendary Death & Company, and refers to something like ice dispensed from a refrigerator or from those 10 pound bags you would usually add to a cooler. Shitty ice is small and melts quickly, providing quick dilution and a ton of convenience. I keep it in the bag (so it stays clean) in a cooler (so it stays cold), and for me, this is the win-win for larger get-togethers.

Now that we've covered the basics of batching, let's get to planning for some Fall gatherings. Tailgating with friends at a college football game? I got you. Relaxing by a fire pit with family? I have just the thing. Hanging out at home with a good book or a movie? Bookmark this page.