I have been on a few time management courses in my career, and one of the things that they all recommend is that you 'touch each piece of paper only once'.
What this means in practice is that if you are doing something that needs to be done do your best to stop interuptions, i.e. no computer, mobile phone etc with constant messages and texts.
Set yourself a target of a sensible end point, obviously if the task can be done in and hour and a half then do it - finish the task and scratch it off your to do list.
If the task is longer term, e.g. a dissertaion or long essay then it is harder to find a suitable stopping point - but it is essential tthat you try. Loads of time is wasted if you stop work at the wrong point. You may have to go over everything you have done previously just to get a handle on where you left off. Finish your point/arguement/section - and have a plan so that you know you can just go on to the next bit then no duplication.
Good luck with the studying guys - glad it isn't me! My son is doing his Highers this year and no one wants advise from their mum and dad - which is a shame because we both have loads of academic experience......
