Browsers make it easy to clear your cache, but sometimes figuring out how to do so takes a little research. Below, you'll find easy-to-follow steps for clearing the cache on your desktop or laptop for Google Chrome, Mozilla Firefox, and Safari. If you're using a Microsoft browser (IE or Edge), you definitely should not be while developing with Oxygen (or for any reason, really).
Google Chrome
Clearing Chrome's cache takes just a few steps. First, navigate to the "Clear Browsing Data" sub item (shown in the image below) to open settings with a popup for clearing data. Chrome has also included a quick-access keyboard shortcut of Ctrl + Shift + Delete to open this page.

Next, simply select "All Time" from the Time Range drop down, check all the boxes, and click "Clear Data." Your browser cache has now been cleared!
More info: Direct from Google Support
Mozilla Firefox
Firefox is one of the most beloved browsers for developing with Oxygen. Fortunately, it also makes things easy to clear its cache. First, navigate to the Options browser page by clicking the pancakes icon in the top right, as shown in this image:

Next, select Privacy & Security from the left-hand menu. Scroll down to Cookies and Site Data, and click "Clear Data".

In the pop up, you can uncheck Cookies and Site Data if you'd like, though it can't hurt to leave it checked. Click "Clear" and you're good to go!
More info: Direct from Firefox Support
Safari
I don't personally do not have Apple, so using Safari is somewhat of a no-no for me. However, according to documentation it is quite easy to clear Safari's cache:
- Click the Safari menu
- Select "Empty Cache" and click "Empty"
Now what?
Now you refresh the pages you wanted to visit, which will rebuild your browser's cache from scratch and (hopefully) fix all the annoying CSS and JS duplications or overrides.