Most of the time when I have artists or writer's block there are two root causes:
- I'm tired or burned out.
- I've got stuck and don't know how to get out of a plot hole or draw something tricky.
In case 1, really a break is the only solution. I find working out or painting some minis (I collect Reaper minis for D&D as well as Warhammer) or hanging out and watching something with my partner is sometimes the break I need to come back refreshed.
In case 2, I usually find taking a totally different approach to the drawing, panel, scene or storyarc helps, like "Okay, this scene where the detective corners the thief in a mansion isn't working because why doesn't she just escape? Also this puts the climactic encounter too early! ... I know! What if we had them meet on the boat on the way to New York! It's efficient because they'll meet on the way to a place the story needed to go anyway, and it'll be more intense because she can't just escape from a boat!" or with drawing, it's often like "HMM, this panel of them interacting looks awkard... What if having it pulled out like this, I pulled it right in looking over this person's shoulder?" or "Ugh, this cover layout is really blah... I'm gonna look at some cool comics covers for inspiration and maybe grab some reference material for poses." Try drawing out a bunch of rough thumbnails that all take totally different approaches to the problem. It usually helps!