Now that I'm in like, one group RP total, I can post once a week and be chill for the rest of it. Sometimes you want to write more, sure, but it's easy for that to snowball into pressure when people start expecting more and more because you got more enthusiasm/time one day than another. Thing is. While I enjoy writing, it saps more energy than it generates. If I do it every day, I won't have time to let my energy levels catch back up to the point I can enjoy it. Honestly, just the aspect of interaction is what keeps roleplaying in and of itself interesting for me. Roleplays that put more focus on exposition of individual characters versus the interaction between them get a pass from me real quick, I've found. It's also that while I've enjoyed my time GM'ing and building worlds, it's far easier on me to play in someone else's world by the virtue of it costing less energy. 'cause turns out not having that kinda break for several years is a lot like slowly sinking my brain in an acid bath. Yeah, my RP's won't die. Boohoo. Poor me. I know :/
Which I guess is a really long way of answering what helps me maintain excitement; enough of a time window to fight posting stress and a lot of interaction with other players during posts.
I generally don't plan breaks or set time limits for them. I let either my whims or circumstances decide it.
I rarely take a break from an RP and come back to it later unless I go on holiday or something, which is hardly ever inspired by a lack of interest in writing. When I do feel a burn-out of sorts coming, typically I start dropping roleplays one by one until I have very few or none of them left. When I do start to feel an itch again, it usually takes me a number of days hovering around an OOC or interest check to commit (or even post in it), so to pick back up roleplaying, I have to have retain interest for that long in the first place... And even then half the time I message the GM I won't commit anyway once the first profiles or IC posts start coming up. Typically, the first RP's I join after a break are the ones I predict to die an early death, so if I don't feel like it anymore after a week or so, I feel less like screwing everybody over.
Yeah. Real nice. 10/10. Would allow to join again. But at least it's an honest answer.