Start from the promise
Write one sentence: what will the listener know or be able to do after this episode? Everything in the outline serves that sentence.
Choose supports
Pick two or three supports: an example, a story, a number or a guest. If a point does not support the promise, leave it out.
Order
Start with what the listener already knows, then move to what is new. Put the strongest point early, since people drop off.
Plan the close
End with the one thing to remember and one step the listener can take. Do not add a second ending.
Add timing
Estimate minutes for each part. A tight outline gives a tight episode, and an editor can work to the plan. A script template adds the detail.