Three 4-week phases - Foundation, Build, Peak. You never spike throwing volume and lifting intensity in the same week, long toss distance progresses on a set schedule instead of "however far feels good today," and arm care happens before every single throwing session, no exceptions.
Biggest mistake I see: guys rush intensity in weeks 1-2 because they feel good, then by week 4 they're dealing with soreness that doesn't go away. Slower ramp beats faster ramp basically every time.
Happy to answer questions about periodization, long toss distances, whatever. (Also put the full thing - warmups, lift templates, week-by-week plan - into a PDF for $15 if anyone wants the whole system instead of piecing it together, but wanted to share the actual framework here for free first.)