You don't need to measure cocktails but you need to measure them to make them well. The 2 sided jigger is what the pros use these days, but has much room for error. However, the 2 ounce total angled jigger from OXO is great for home use because you can build the whole drink in the jigger.
Most cocktails are scaling down these days and that it a good thing. You don't need a 6 ounce martini on a bad day— you need 3 martinis. Smaller drinks stay cold and their quality will stay in tact while drinking. Thus, fitting your recipe into a 2 ounce jigger is recommended for people learning cocktail templates.
However, jiggers don't make drinks just "work" citrus changes geographically and even throughout he day, different brands make different cocktails and some recipes just aren't very good. Taste you drink to make sure they are good and measure them to know how to change them.
These are what we now call 'big fucking cubes" but they are really all you need for making drinks at home. Depending on the size of your shaker/stirring glass, you'll only need 2 or 3 cubes (cracked with a spoon) to fill the glass. That is to say: 2 cocktails can be made with each tray.
That may seem excessive, but that is how drinks are made well.
To crack an ice cube, use an ice crackeror, just hold it in your hand and whack it with a spoon or a muddler. You will miss a few times, hit your hand, call me a fuck, get bruises, but eventually it will be easy and your drinks will be perfectly chilled and diluted.
If a cocktail is all spirit, that is to say: you can see through it, stir it. If it has juice or non alcoholic mixers: shake it. The world loves sours; Margaritas, Cosmopolitans and Daiquiris. Nerds increasingly turn to the darkside of stirred Gin, Amari and Aromatized Wine cocktails. This is a case in which both side need to learn more from each other but I digress.
You will get great satisfaction stirring a cocktail in a giant glass pitcher. You can smell the silence, hear the cold and see the aroma— that is just how beguiling to the senses a perfectly stirred drink is.
Most of the sexy stirring glasses are coming from Japan these days. But I am personally loving these Bull in China, made in America, rustic and sturdy stirring glasses. They cost more, but I'm expecting 10 times the life out of them.
If stirring a cocktail, use a julep strainer. When showing off, I will occasionally use a barspoon to strain (you'll need big ice). But until you want to pull of that bullshit move, keep it's simple: julep strainer works with glass.
This is not a zester, a zester is any number of other culinary tools that is not this. The channel knife went out of style for the y-peeler 10 years back. I pretty much only use them for Vespers (long thin slice of lemon) or for quickly peeling an entire lemon when making a half dozen zests at once.
The channel knife is an atavistic tool, but I still value them.
This is not an either or, I use all 3 of these y peelers. Rosle cuts a light, no pith zest, it's razor sharp and creates delicate garnishes. The Swissmar is the best all around, it's cheap but puts a lot of pith in the drink with is unacceptable for subtle cocktails. I use the burly Uber Chef peeler to zest grapefruits but it is capable of zesting durians. But the real use of this battle axe is cutting cucumbers or carrots into thin ribbons.
It's really a joining mallet, for wood working. My dad gave me mine when I was 14, he told me to carve a totem pole with it. That piece of appropriated culture is still in my parents guest room today. But if your dad wasn't Ron Swanson, you'll need to buy a mallet for crushing ice.
Don't buy a rubber mallet, it will just bounce back at you.
Get a wooden, maple or walnut joining mallet and it will last a lifetime. But, you'll need a lewis bag for crushing that ice...
Unless you are making a few dozen cocktails, just squeeze fresh fruit as you go. Halve the fruit, cut the nib on the end off and score the center of the fruit with an "x." These steps will make it so a little baby could squeeze the coldest, unripe limes with ease.
The second commercially available bitters is likely #1 in red #5. Insults aside, Peychaud's is a very distinct tropical bitters that exceeds making cocktails red and drying out their flavor. It is essential in many classics and very difficult to replace.
Most likely what those tiny James Bond Martinis were being served in. There are production stills of Sean Connery drinking from Nick & Nora glasses. It really lends itself to tossing a drink back quickly.
This is what all the twisty mustache places use these days for cocktails. The coupe helps focus the nose of a stirred cocktail and allows bold gestures from someone who talks with their hand while drinking.
If it has bubbles in it or is a cocktail with juice built over ice: use a highball glass. Some of the drinks you'll like more in a highball? Gin & Tonic, Collins, Rum & Coke, Sea Breeze, Americao even a Madras; they will all be better out of a nose focusing highball glass.