in 1975, british painter and color theorist peter schmidt, and legendary musician brian eno, found out that the other had developed the same solution for creative frustration.
the two had indepdently come up with decks of index cards they would keep in their studios, on which they had written “a set of basic working principals” which would help guide them through moments of artistic pressure.

here Eno discusses the origins of the Oblique Strategies:
“These cards evolved from our separate working procedures. It was one of the many cases during the friendship that he [Peter Schmidt] and I where we arrived at a working position at almost exactly the same time and almost in exactly the same words. There were times when we hadn’t seen each other for a few months at a time sometimes, and upon remeeting or exchanging letters, we would find that we were in the same intellectual position – which was quite different from the one we’d been in prior to that.
The Oblique Strategies evolved from me being in a number of working situations when the panic of the situation – particularly in studios – tended to make me quickly forget that there were others ways of working and that there were tangential ways of attacking problems that were in many senses more interesting than the direct head-on approach. If you’re in a panic, you tend to take the head-on approach because it seems to be the one that’s going to yield the best results Of course, that often isn’t the case – it’s just the most obvious and – apparently – reliable method. The function of the Oblique Strategies was, initially, to serve as a series of prompts which said, “Don’t forget that you could adopt *this* attitude,” or “Don’t forget you could adopt *that* attitude.”
The first Oblique Strategy said “Honour thy error as a hidden intention.” And, in fact, Peter’s first Oblique Strategy – done quite independently and before either of us had become conscious that the other was doing that – was …I think it was “Was it really a mistake?” which was, of course, much the same kind of message. Well, I collected about fifteen or twenty of these and then I put them onto cards. At the same time, Peter had been keeping a little book of messages to himself as regards painting, and he’d kept those in a notebook. We were both very surprised to find the other not only using a similar system but also many of the messages being absolutely overlapping, you know…there was a complete correspondence between the messages. So subsequently we decided to try to work out a way of making that available to other people, which we did; we published them as a pack of cards, and they’re now used by quite a lot of different people, I think” stealing beauty divx download
Until recently, you could either buy a replica deck, or scour the internet/earth for first editions.
Now thankfully, someone has released a version of the Oblique Strategies deck, including all five incarnations, as an iPhone application.

It’s free, and the perfect thing to have when getting stuck creatively, when you’ve run out of things to say on a date, or as a last ditch hope as you string yourself up to the laundry dryer in your kitchen.
more info on the deck, incarnations etc, here, and here.