1) Organize the thing you need to get done into smaller pieces so that it's not so overwhelming. If you have a bigger project deadline in a few weeks, do a little bit each night and specify how long you'll spend each night.
2) Start with things you enjoy rather the things that you don't want to do. Once you get started, you'll have the momentum to get through the things that aren't as enjoyable.
3) Get rid of any distractions you may have. Constantly texting your friends or on social media? Turn off your phone and the notifications so you aren't distracted. Go to a quiet room without a tv. Put on a little soothing music to get you motivated - and get to it :).
This is a good video in case that's easier to digest. Keep it simple - don't overcomplicate it. Good luck!