I used to be a procrastinator until I learned a valuable lesson while on March break in the 6th grade. You see, march break was two weeks long back then, and we were given this huge pile of homework to do while on vacation. Of course, I didn't start it until the last sunday night. Everything hit me like a tonne of bricks - it was one of the most devastating feelings I've ever felt. I ended up finishing the work with the help of my older sister, but I was so tired by the end of it that I missed going to school the next day.
Anyway, ever since then I've stopped procrastinating. All it takes is one really negative experience to shock you back into not-procrastinating ever again. I really needed to go through that traumatizing event to learn the pitfalls of procrastination.
Really, do assignments as soon as you get them. Put off fun activities until you finish the ones you need to do. I've found that if I do put something off it'll be on my mind the whole time and as a result will diminish any fun I choose to have instead. Once something's complete I can fully devote my mind to other matters, and it's so much better as a result. Having experienced both sides of the spectrum I still don't know why anyone would willingly choose to procrastinate. Getting things done way in advance is SO MUCH more better and relaxing.
I'd say the easiest way to overcome procrastination is to write yourself a checkbox schedule of things to do. Be specific though. Don't say "study biology", but rather "study chapter 8 in the biology textbook". Divide big tasks into chunks that you can do each day.
I've been trying to stop procrastinating, but I have a back-up of work, I like to finish things in a single sitting, this means if have a large sum of work I push it further because I feel like in the back of my head that if I start I wont stop till I'm exhausted and probably wont finish though I worked so much also probably rush a lot of the work in the process... and this makes me REALLY not want to do it... so I end up not doing it, and since I also like to do work IN ORDER of when I get it, if I get a assignment that I hate particularly, I wont end up doing any of the work my other classes till I finish that one, which ends up taking a while cuz I just put it off, and off...
I also have difficulty just doing little by little because I lose things. Why does this matter? My flash drive, I've left my flash drive in my schools computers 5 times in a single week before (each time it showed up at the lost and found) so doing a little then saving my progress makes me paranoid. I also sometime can't find the right file or I'll forget that I even did the work and end up starting over...
I also put off doing ANYTHING else sometimes just because in the back of my mind I realize I have work and don't do any fun stuff AT ALL in order to avoid the guilt of not working, and I end up not doing anything... at all... I just go with the flow... or surf the internet randomly...
I wish there was I way to just fix it quickly and easily with out any extra consequences.
EDIT: I terribly sorry for this horribly written post... I haven't slept in a while.