If by 'writer's block' we are talking about those times when the mind cannot engage in a work in progress, when the ideas are not there, or when they move in a circular manner, I generally deal with that by doing a bit of editing. Editing turns my attention to technique and angles it away from direct creativity. After an hour or so of editing the creative energy usually returns.
If we are talking about those times when it seems absolutely impossible to get down to writing, when the mind reacts against the very thought of writing, then I think I would handle that by reading. Not something new but something that refreshes me, like "The Wind in the Willows". The second type of writer's block hasn't happened to me, thank goodness, and I hope it never does.
I attend a weekly writers' group and I've heard that if you're forced away from writing, through a stay in hospital, for example, or a family crisis, it is very hard to get back to the writing routine. I can't imagine a day when I don't write anything. The very thought makes me shiver.