Choosing a palette before a pattern
For a long time I picked colours last. Now they come first, and the patterns get simpler for it.
A pair of colours decides the mood before the geometry does. If the two inks are close in value, the fringes stay soft and quiet; if they are far apart, every line fights for attention.
These days I pick the background first, then one dark ink, then an accent that is a little warmer or cooler than the dark one. Only then do I touch the spacing.