On reflection, this probably isn't the best example to lead with - the effect doesn't photograph quite as well as something using paint/stain (I wanted to keep the wood's colour), but the techniques used are the same.
I decided that I wanted another shelf up in my office - I've some nice Victorian train style shelf brackets, and plenty of scrap wood to call upon.
By luck, I found a length of pressure treated 2x4 that was already the perfect length.
But, it did look quite a lot like I'd taken a piece of scrap timber and bolted it to the wall (funny that...)
Functionally, it's a shelf, but it really is quite rough. What I quite like, though, is the mix of colours - along with the wood's natural mix of colours, parts of it have a slightly green hue (because it's pressure treated).
So, I decided I'd have a go at distressing it - making it look like it was actually a shelf, but had seen some life.