So, people don't magically recover from having once been a procrastinator when they enter grad school in their dream field? Uh oh, bad news for me....
But, seriously, I feel energized when I have something new to do. (Which is why I'm not in a field requiring lengthy research, but instead usually very short-term projects. But I've seen people in lengthy research fields struggle the same attention-span issues I have. And I feel for them!) When I do have to conquer a long-winded project, I try to find other new, exciting things to do with my spare time, to make up for the agonizing project.
Sometimes taking a brief break for an outdoor adventure, someplace I haven't been, is all I need to come back home and focus focus focus! Or treating myself to a silly movie. Or trying a new restaurant and bringing some of my work with me -- I can work on almost anything if good food's involved!
I don't save special things as rewards for doing my work, because then I'm sad looking forward to them, still procrastinate, never earn the reward but probably go get it anyway.... So I reward myself in advance and then get to work.
When that doesn't work, I try to find a friend who's interested in my research topic, and talk it over with them. Their energy can be really motivating and inspiring.
If I really still have a hard time, that means I need to tweak my research topic to something that will better sustain my interest. In general, I find it's better to tweak the topic sooner rather than later, because my disinterest will only grow over time. I finished my undergrad thesis last semester, and I actually altered my topic mid-way because, well, I was reading blogs, too, and I am not someone who reads blogs! My thesis turned out great with the revised topic, but I can only think of how great it could have been if I'd changed my topic earlier on, rather than being stubborn and sticking with something that lost its magic within the first month of research.
If you're drifting at this early stage, maybe you need to spice up your topic, too. I think early on should be the most fun part -- until you're almost finished and you're editing it!