The first way to write a novel happens when you get an inkling of some kind of slime lurking just out of reach round a dark corner in your subconscious. So you put your hand into the hollow trunk and bring it out into the world. You quickly try and daub it onto paper before it dissolves. It does not spread through the whole book, of course, and it diminishes over time, but some of it remains somewhere and you can always look back at the smears of the original slime and use the smell to help you in the dark .
The second way to write a novel is what everyone else is told to do. You plan a plot and break it up into ten sections. You put a car chase here, a break-up there and a sad bit somewhere else. Then you get some ribbons and bows out and wrap up the package. This way is not much fun, but it is simple in a clever way. It is like folding a sheet of paper a few times until it becomes a paper airplane and you find it can fly quite a way.
The third way to write a novel is when you have a yard with a lot of old wrecks in it. There is a bit of old car engine here; there is a mangle there; then there is a rusty lawn mower near the edge of the concrete; there is a coffee grinder near the road. You need to be a bit of an engineer for this novel because you have to screw them all in together so that when you crank up the mangle the engine runs, the grass is razed and the coffee ground. If you are successful with this novel, all the bits make a creature.