A story consists of a platform, which is the initial conditions (people, place, relationships, time) and the unpacking of the platform: reusing, as cleverly and interestingly as possible, the various elements of the platform or their direct descendants. Bloody hell, even I can't quite make that out! Example: two men on a bus= bad platform. Two men on a bus, one hasn't paid for his ticket and the conductor is coming= slightly better platform. Two men on a bus, one ticket between them and the conductor is coming= a tad better too. So you get the picture: the platform is your pandoras box, your dressing up cupboard, your chest of goodies that you can mix and match to the reader's delight. The later on in a story you introduce a new element the more you stretch the platform out and into the unpacking of the platform. This is usually bad and makes the story read like a series of 'and then I did X, and then I did Y'. It doesn't matter how interesting each element is, without the glue of unpacking and reusing of what has come before the audience will lose interest.The chiefdelight in hearing a story is the clever reuse of something glimpsed earlier. Think of Piggy's specs in Lord of the Flies, the Ring in the Hobbit, and every gagg structure used by Charlie Chaplin. Unpacking and reusing elements of the platform are how we 'understand' the basic materials of the story. A 'three act' structure is nothing sacred- it's just this: the platform, elements of the platform going wrong, the same elements going right. The five act structure is more pleasing because we get an extra go at the elements with the 'false victory' that happens in the middle (Act 1=platform, Act 2=bad stuff happens, Act3=false victory, Act4=all hell breaks loose, Act5=a climactic struggle leading to final victory or utter defeat).
Interesting platforms lead to interesting stories. Forget what you can drag in later. If it 'aint in the platform get a new one. Hated notions such as the 'hi concept' movie have something right here. A high concept platform is probably a fruitful one, other things being equal. If you can repeat the platform to someone without embarrassment it is probably a good start. If the platform seems to DEMAND explanation (like the marvellous 'hundred year old man who leapt out of a window') then you are onto something.
The tip: create platforms that seem to demand further explanation.