for my book, if I have writer's block, I look at random details I've added to see if any plots can come out of them. I try and make 'filler' plots so everything isn't rushed, and that can help get rid of writer's block too. I still get it though, so I wait a week or so, and try to brainstorm.
Same here except I do something differently. I would just read over what I had written and try to get back in the mood. Usually reading over what you have written so far will get you in that same state of mind that you had previous to getting writer's block. It helps for me especially if I've taken a few days off of writing and I've completely forgotten what the current chapter was about or what part of the chapter I was stuck on.