Vodka

Vodka is an European clear distilled alcoholic drink that has been one of the most popular drinks across the world .

You'll find it to be the most popular spirit in drink making because of it's neutral taste and absence of flavour and colour.

Vodka often replaces Gin in many traditional cocktails

Vodka is known to be good for the heart, and if consumed in moderation, can prove to be good for cardiovascular health

Note that these days there are flavoured Vodka available in the market too, and some cocktails do make use of them.

Orange Juice

Orange Juice is an excellent source of Vitamin C, one cup contains twice the daily recommended value. Vitamin C supports the immune system and helps fighting the common cold. The folate in Orange juice supports healthy fetal development. It is low calory and thus is already a qualified alternative to cola fizz in your cocktail if you want to keep your drinks acceptably healthy.

Orange Juice being citrus and naturally sweet and sour, it literally goes with almost any liquor, and of course Vodka being neutral, the best known pairing is with Vodka. But goes well with Dark Rum too, and you get the Planter's Punch, mix it with Champagne and you have made a mimosa, or with tequila to make a tequila sunrise.

Sugar

Brown Sugar is a sucrose sugar with a distinctive brown colour from the presence of molasses, it is a partially refined or unrefined sugar containing sugar crystals and residual molasses giving it a distinctive taste and flavour of crystallised molasses or toffee. The taste of dark brown sugar is described as a caramel taste with a deep molasses flavour.
Brown sugar is used in cocktails where a caramel candy or toffee flavour is expected.

Caster Sugar is finely ground granulated sugar. It is not as fine a powdered confectioners' sugar and has a little grit to it. It is somewhere between confectioners' sugar and granulated sugar, and melts in mouth with a mild spicy feel to the tongue

Vanilla Sugar is the regular granulated sugar infused with vanilla flavour, by using vanilla pods and seeds to flavour the sugar. A home made alternative is to use vanilla sticks or pods in a jar of sugar and leave it sealed for 4 weeks to allow the vanilla flavour to infuse. Or to use granulated sugar and vanilla extract and blend in a mixer, although this ends up in powdered sugar.

Egg Yolk

Eggs are used to add viscosity and mouthfeel to cocktails, sour cocktails like Whisky Sour, tastes the best when made with added egg white. Egg whites create a creamy texture and a thick layer of foam on top of a cocktail. While unlike using just the white, adding the yolk adds a bit of a flavour to the drink, it helps emulsify the other ingredients and adds the eggnog flavour to your cocktail.
To get the silk smooth texture and mouthfeel and the foamy head without weakening the drink by melting the ice from too long shaking, which is needed to break the proteins of the egg white to froth up, dry shake the ingredients first, that is, pour all ingredients and the egg white in your shaker and shake hard without ice first, for about a minute and then add ice and shake again.