The shaking of a cocktail can make or break the finish of a good drink. The most common shakers used in bars are called 'Boston Shakers'. These take some practice to perfect and are definitely not for beginners.
Most at-home shakers are called 'Cobbler Shakers'. These are relatively easy to use and easy to find in stores. However, you can also opt for using any sealable, cylindrical container at home and save your money for another bottle of Gentleman Jack.