Buy a good mixing vessel to concoct your drinks in. This will allow you to expand your recipes and drinks with different textures, dilutions, and ingredients. You can use a Mason jar as a shaker. It'll work okay. Likewise, you can just make built drinks or stirred drinks in whatever glass you have. But similar to a jigger, the right equipment helps you to be more efficient, to make repeatable drinks, and to generally have a more enjoyable time.
A proper mixing vessel ups your cocktail game in three ways:
Every drink requires a vessel to mix in. Importantly, the right vessel will bring practical benefits to what you can make.
With shaking implements you have four categories to choose from:
For stirring, there are glass and metal vessels that resemble beakers. They are cylindrical and flat bottomed, produced in a variety of styles, including decoratively cut glass. Frankly, I don’t like them because their practicality is limited. As such, I won’t be covering them here.
When it comes down to it, assuming it is metal and of sufficient volume, what you shake in doesn't matter. Shaking is a chaotic, rapid technique that will produce the same results no matter what you use. If it isn't metal, and you want to stir with it, keep it in the freezer to produce similar results.
My preference is mixing tins. With a cobbler, the top gets misplaced and the seal can sometimes be tricky to break. I like the feel of shaking with a mixing tins more than a Boston shaker. The larger volume of mixing tins allows for a larger surface to volume ratio when shaking, which leads to more aeration. I like that I can stack multiple sets of mixing tins to conserve space in my bar cabinet. I like that I can use one mixing tin set to stir three servings of one drink and two servings of another. Mixing tins just beat out the other options due to their utilitarian nature. I use mixing tins for almost every drink I make. If I don’t use them for mixing, I’ll use the tins for measuring my ingredients into, thawing syrups, and heating ingredients. They are indispensable.
I have a set of mixing tins that seal fantastically and feel great when throwing ice around. These are a Cocktail Kingdom’s Koriko Large 28 oz Tin and a Cocktail Kingdom’s Koriko 18 oz Tin. The shipping costs on these are ridiculous. As an alternative, you can save a few bucks with this set of A Bar Above's Premium Weighted Cocktail Shaker Set which is almost as nice as the Korikos.You only need one set to start, but if you get into slinging drinks your collection will likely grow. I have three sets because they get used so often, and regularly at the same time.
Can you get a Boston shaker, cobbler shaker, or Parisienne shaker instead? Sure, those will work just fine and probably just as great. My personal preference is towards the mixing tin and I have given away my cobblers and rarely use a Boston shaker. Although when I do use a Boston shaker, I do so by pairing one of my 28 oz mixing tins with a pint glass - there’s no need to buy a specific Boston shaker set like the one linked above. Otherwise, I simply prefer mixing tins for a few reasons:
Of course, you can opt for sweet looking Japanese style mixing glass, like the Cocktail Kingdom Sokata Mixing Glass. Aim for a size near 25 oz which will be adequate for stirring 3 servings at a time. There are specific metal variants too, like the Cocktail Kingdom Mixtin Stirring Tin, in similar shapes, but they provide no clear benefit over just using the base of a mixing tin. Remember, these are only useful for stirred drinks. Since stirring is a more controlled technique, the vessel’s properties will have more of an impact on the drink’s outcome than when shaking. With your stirring vessel, you will need to take into account it’s thermal mass. A larger thermal mass requires more energy, absorbed from the colder or hotter temperature of the vessel’s contents (your drink). Glass has a higher thermal mass and will absorb the coldness of the ice in your vessel, which will impact your drink by requiring more stirring time. If you use a glass vessel to stir, keep it in the freezer between uses. I don't have that luxury since my freezer is packed with waffles, bananas, berries, bacon, and ice. You don’t have to worry about this with metal, which has a much lower thermal mass. But hey, if you’re doing that, you might as well just use the base or tin from a shaker to stir in. On practicality, again, the mixing tins for the win!
As you get more into drinks and build it your bar you'll want to remember this maxim from attributed to Trader Vic:
“Spend time with your guests - not making mixed drinks.”
If the equipment can make it more efficient to make a drink, you’ll spend more time enjoying it and who you’re making it for.