Disabling background applications that cause problems will help improve the performance of Rocket League. Performing a clean Startup will help determine if there are specific background applications that are causing problems.
For more info, check out: How to Perform a Clean Boot in Windows.
Closing programs that require bandwidth, like chat clients, streaming services, or web browsers, will help even more. Programs running in the background may cause Rocket League to play choppy or cause other performance issues.
If you are following the series of articles in How do I fix graphic problems and frame rate drops in Rocket League? and this did not solve the issue try the next step in our troubleshooting: How do I adjust the in-game video settings in Rocket League?