A cobbler shaker is the easiest style to use and therefore the most commonly seen in at-home bar kits. It has everything you need to shake and strain so just follow these easy steps.
Assemble ingredients in base of shaker, then fill with ice.
Fit shaker with strainer top and cap to seal.
Hold base of shaker firmly with one hand and top of shaker firmly with other hand. Using vigorous back-and-forth motion (ice should hit both ends of shaker), shake cocktail for amount of time specified in recipe.
Remove cap (you may need to loosen by gently tapping on counter) and decant cocktail into chilled serving glass, using conical strainer to double-strain if directed.