The solution may have multiple implementations based on your maturity and self-awareness. From most mature and self-aware, they are: Schedule, Bargain, Time-Limit. Each has been shown to have efficacy in my coaching practice.
Schedule your time in 30-minute increments each day. Make sure to include time for things that energize you. Pay specific attention to things that increase your endorphin levels like exercising. Schedule your important tasks by their component parts not just the overall tasks. For example, a term paper would have components like literature review, draft composition, editing, writing center, revise, final draft submission.
Make a deal with yourself that you will give a certain amount of time to something that is pressing—a class assignment or challenging task like filling out a form. In exchange for that amount to time, you receive time to spend on an activity that makes you happy. Something fun. You can engage in the activity without guilt because you put your time into the pressing activity. Continue to alternate until the pressing activity is completed. For example, you can bargain that you will work on homework for 30 minutes. In exchange, that 30 minutes purchases you 60 minutes online. If you stick to your bargain and alternate, this works.
This is like the bargain, but different in that it does not require a fun activity relationship. It also is completed with the help of a timer. Set the timer to a certain time and start it. While the timer is going, you commit to