My son is a fairly typical 16 year old. As such he'd found it really hard to be disciplined about revision (added to an ever growing list that also includes picking up after himself, putting empty glass into the dishwasher, etc!).
In a bid to encourage good studying behaviours ready for A-levels and beyond I've worked with him to create a nifty more engaging way of scheduling tasks. Its based on an agile project management style I use in my work. There's also a spreadsheet that helps track tasks.
I wanted to share my experience and wrote it up on my seldom-updated personal site. I can't promise that your own little darlings will suddenly become consciencious and study hard, but it has certainly helped mine get a bit more focused.