Something not to do if you're feeling a bit anxious about all the work you're not getting done this summer:
Read anything written by your dissertation advisor. You will then hear her voice asking you questions about all the work you're not doing, and will start imagining the next time you're likely to meet her and all the amazing things that you'll really need to have accomplished before then so that you can hold a conversation with her. Meanwhile, as you're conjuring up better and worse versions of this scenario, you still won't be getting any work done.
And if you must read something written by your former advisor, because it's essential to whatever you're currently not-working on, at least don't let that something be really, really great, and so much better than your own attempts to grapple with similar material.
(Needless to say, no one gave me this advice, but you should feel free to learn from my mistakes.)