What should I look for in an undated planner if I have ADHD?

Threads on r/adhdwomen and r/planners consistently flag three things: flexibility to skip days without guilt, simple layouts without forced habit and water trackers, and enough blank space to customize. Undated planners are popular in those communities precisely because missing a week doesn't waste pre-printed dates. Spiral-bound layouts that lay flat also come up repeatedly as ADHD-friendly.