Well, the thing is, its very Maladaptive, it causes you more problems than it fixes, trust me, I know. Im my GCSE art course, I spent most of the year doing tiny little amounts of the necessary work, leaving things to do for later. When the end of the year rolled around, I bailed out of entire class study sessions just to finish my art. Thankfully, I'm a fast learner, and I managed to do very well in my classes, but for those final weeks of school; It was a complete nightmare.
This year, I don't have the luxury of time, I need to work fast and hard, straight off the bat, so I have to learn how. The majority of you aren't going to be in this position right away, you might be able to relax and leave it to the last minute. Please for the love of anything, DON'T DO THAT.
We're going to learn this together okay?
Personally, I excell closer to deadlines, so if you're like me, set yourself deadlines. Put 2-4 hours on an alarm and work as hard as you can for that time. Once you're done, that's it. Those are your notes finished for that work, thats your poster done, thats your coursework finished. Set yourself specific guidelines for what needs to be completed in that time. If you can't de-clutter your mind, a change of environment might be more helpful, try taking over the livingroom to study, or maybe go to the local library. (yeah, those things still exist, it's kinda weird.)
You could also enlist people to help. Get your parents to encourage you, or your friends/classmates to form a study group with you. My friends said to me multiple times that the anxiety they face from being placed in a study group makes them study harder, in order to fit in with the group. Sure the anxiety doesn't sound fun, but if it's helping you like anxiety actually should, I guess it's okay.
Don't forget you should take a 10 minute break every 30 minutes, since it's been proven to be the best ratio of work-rest. You can't overstress yourself, or the information won't go in, and it'll all be for nothing. You have to care for yourself, take it easy, and don't over complicate it all.
The thing is if you get into the habit of working through it now, It'll save you a lot of time later. If you get into the habit of leaving things to the last minute it'll be a lot harder to break out of it.
Consider setting aside a few days a week, make a routine so that you can stick to it for longer.
If you start now, you'll have more time to spare later, and less stress when exams and deadlines come. Come on guys, we can do this.