Have three competing novel ideas and I'm paralysed about which to start next.

1. Literary dystopian
2. YA fantasy - contemporary
3. YA fantasy - ancient world

All else being equal, which one would you prefer to read?

Writer of YA fantasy and commercial women's fiction

You could write a sentence about each idea, and then a paragraph and then design characters etc. 

At some point you will feel a natural gravity towards that thing that you want to pursue next.

This is the alt account of Sister Hazel. Writings at https://powerlaw.systems

That's an interesting approach, I might try it, thanks!

I usually don't start writing until I have a full scene-by-scene outline which is pretty much the opposite of the above, but it might get the juices flowing enough to figure out what I want to do.

On a spreadsheet, as a dot point summary, not as prose. 

I find plotting and execution to be two entirely different exercises, using different parts of the brain, and don't like to mix them up.

How do you create your scene by scene outline if you are not writing it down?