Here's how I tackle layout and workflow concepts.
Do something. Anything. And do that thing knowing that it doesn't have to be good. It just has to exist. It's not an end, it's a beginning. It's just a way to stop you from staring at a blank page.
Then do an alternative design.
Quickly. Don't think about it too much.
Then another. Don't despair if they're bad. You're simply riffing. You're emptying your head onto the page, so you can try to construct something good from the bad.
Use whatever technique or medium lets you create concepts quickly. It doesn't matter if that's pen and paper or software. I find that being able to throw lots of alternatives near each other is good, so that usually means paper, an iPad app like Procreate, or Adobe Illustrator. A big canvas is good.
When you think you have a good design, pretend it's a competing product — pretend that you can not use that design and that you have to come up with something different.
Then do that again.
After the frenzy, you can sit back and let yourself critique the work. Tear it apart. Beg, borrow and steal from all your alternatives until you have created a hybrid, winning layout.
I started my career as a finished artist and retoucher, being the hands for ad agency Art Directors. I'd have to do what I was told and only occasionally offer input. There was one Art Director in particular who I ended up working with quite a fair bit. An older guy who seemed to stumble though his work. To me, he didn't seem to know what he was doing. He'd just bounce around, back and forth and eventually get to something that may or may not be final. It felt like he was taking a scenic route where a more direct path could have been taken, saving hours of work.
And then I started to realise something — he'd intentionally try different and crazy things, knowing that most wouldn't work. He didn't care. In doing so, we'd end up in places we never would have got if we over-thought things. We'd end up with designs that worked, but seemed a little unconventional. Except when we didn't. And that was fine, because we'd know the path that had been taken, and exhausted many alternatives. There was some certainty in knowing the design was good in comparison to all other possibilities for the elements at play.
He was a great mentor and I now use a very similar technique. There's so much value in learning by rapidly exploring.
When you have nothing, do anything. When you have something, do something else.