Functional jazz moves toward something — a ii chord leans on a V, which resolves to I. Modal jazz drops that engine entirely: pick one mode, sit on its tonic chord for a long stretch, and let the mode's own color carry the piece instead of a chord-to-chord pull. There's no dominant to resolve, so there's nothing to "resolve" — just one static harmony worth exploring. Pick a root and a mode below.
A shape a handful of modal standards share — "So What" and "Impressions" among them: two 8-bar stretches on the tonic mode, an 8-bar bridge a half step higher, then 8 bars back home. This is the generalized shape, in whichever root and mode you've picked above — not a transcription of either tune's original key or melody.