1. I'd make a timetable, try to arrange the hardest subjects you find first. Don't run away from it or leave it till later. Make a sensible timetable, not 5 hours straight of ........without any rest. Don't exceed your limits. every 1hr you take a short 5-10 minute break.
2. Notes, use colour, get creative with pictures and illustrations, making dull notes on the page will not motivate you to work. if you get bored with reading, why not try to watch a video on the subject? for example, if you're doing history watch a documentary about the topic. If you're doing maths, try YouTube, which has a lot of useful videos, same thing with science.
3. Lock your phone away, furthest room possible turn of the power, so it'll have to take some effort for you to get up and get it. So you wouldn't resort to peak at your phone and break your concentration, which is important for you to maintain.
4. JUST GET ON WITH IT! Don't be like me..i always say..i'll start revising in 10 minutes...believe me...the 10 minutes will soon turn into 10 hours! maybe even 10 days.
I wish you do well in your exams
You will have all summer holidays to relax and have fun, this time is for revision.