The vocabulary problem
Paywall copy often describes features when it should describe outcomes. 'Track expenses' is a feature. 'Never miss a bill' is an outcome. Test the two framings on your own audience.
The anchor and the ladder
Show yearly first, monthly as the smaller alternative. Anchor with a struck-through 'was' price only if it's genuinely a promotional price, false anchors are illegal in the EU and hurt trust everywhere. Use a three-tier ladder only when tiers are truly differentiated; otherwise a single yearly plan converts higher.
Trial mechanics
Seven-day free trial converts better than three-day for most productivity apps; three-day converts better for utility apps. Streaming and casual gaming recurring plans benefit from a hard paywall (no trial) with a lower price point. Test category-specific.
Localisation of price
Currency, local price presentation and payment-method availability can all shift conversion. Test locally familiar price endings and payment options by market.
Test cadence
Quarterly paywall test cycles. One variable per test (price, copy, layout, never combined). Winners ship on the next release.