The best advice I can give is to make a conscious decision to get rid of all distractions when you want to revise. Personally I gave my laptop to my dad on a 9.30->6 schedule during study leave for A2s. If TV is your thing, tell your parents/whoever to stop you watching TV if you start during certain times.
The worst thing you can do during the run-up to exams in pseudo-revise, by getting constantly distracted. At the end of the day you'll feel like you've done a full day's work and gotten little out of it, and potentially get demoralised (making things worse). Revise when you're revising. When you take a break, relax completely. You have no idea how many people believe they are less intelligent than they are simply because they haven't learned how to get rid of distractions.
Honestly the scheduling doesn't matter. I happily revise 6-8 hours straight with maybe a half hour break, but some people are better with hour-long bursts. As long as you make the decision to get rid of distractions and focus, you'll do well.