Even when you take a break from your actual project, it's often a good idea to take a little time doing things that are still somewhat related to it. As an example, right now I'm reading and running Tenra Bansho Zero (a delightful English translation of a high action Japanese RPG). I'll soon be receiving Call of Cthulhu 7th ed. (hopefully), re-reading portions of Achtung Cthulhu, running a Cthulhu Dark adventure (which should teach me something about rules purity), playing a little Pathfinder and tinkering around with Blood & Smoke until I get a LARP out of it.
I'm also playing horror videogames (Deadly Premonition, Outlast, Haunted Memories), a dark action videogame (latest Tomb Raider) and have finished Beyond: Two Souls (a neat psychological drama with horror and science fiction elements).
This is a very important part of the process because if you keep tinkering with the same thing with no external inspirations, tests or understandings, your focus can narrow again and again until you lose sight of what you initially intended.
Naturally I'm still playtesting my system with Masks of Nyarlathotep though I haven't run a session in a little over a month. I'm also playtesting the feel of a Horrors campaign as well, which is ironic, because it's a) something I didn't realise I had set out to do, and b) not something you expect to do with a massively pulpy pre-written campaign. But there you go. There's the backdrop of mundane action and character rich setting with through-lines that can be both mundane (find a home), criminal (prologue: stop the eugenics cult) and paranormal (prologue: cultists have magic powers and mutant humans, though this hasn't taken center stage yet).