I'm a grad student who has also just helped start a company, so naturally I end up with lots to do. But large lists can overwhelm me, and I can tend to habitually ignore certain items. So here's how I've been using RTM lately (slightly idealized):

I have "bucket lists" for Personal, Research, Company, etc., which are tagged and prioritized (but "Due Dates Must Be Real."). But my actual lists are by location: AtHome, AtLab, and Errands. At the beginning of each week, I clear out the location lists, go through each of the bucket lists, and select a few of those items to add to the appropriate location lists. And of course I tweak these lists throughout the week.

Smart Lists help me build the location lists, but I rebuild them each week to make me reflect on my goals and tasks -- which makes me more likely to actually follow through with them!

I also use the RTM Android app to note down anything I think of on the go. It ends up in my Inbox and due today; when I get to my desk, I go through my Inbox, fixing due date and moving items to the correct list. I also endorse the A Bit Better RTM extension, which makes moving tasks between lists so much easier.

And though it's been said many times already: make your todo's actionable! That used to be my biggest reason for ignoring something :)