Step 1: Head to the Settings menu. This can be done by tapping the cog icon in your notification shade.
Step 2: Find Apps (or Applications, depending on your device) in the menu, then locate the app that you want to clear the cache or data for.
Step 3: Tap on Storage and the buttons for clearing the cache and app data will become available (pictured above).
There are apps on the Google Play store that can perform this function for you, but constantly clearing your cache isn’t likely to give you the speed boost they all promise. Performing this function manually means you’ll only clear out caches or data from apps that you recognize as storage hogs, and prevents needing to add yet another app to your collection.