Automation should reduce meaningful delivery risk and repeated manual effort. That means prioritisation matters more than raw test count.
Start with business-critical paths
Authentication, purchasing, payments, core transactions, permissions, and other workflows that would materially affect users or revenue are strong candidates when they are stable enough to automate.
Look at repetition
Scenarios executed every sprint or release usually provide more automation value than checks performed only occasionally.
Consider maintenance cost
A scenario that changes constantly, depends on unstable third parties, or requires difficult test data may be a poor early automation target even when it is important.
Build a useful smoke layer first
A small set of fast, dependable checks can provide earlier delivery value than a large regression suite that takes hours and regularly fails for non-product reasons.
Use the right layer
Not every check belongs in browser automation. API or service-level tests may provide faster and more maintainable coverage for business rules and integration behaviour.
A practical prioritisation question
For every candidate, ask: how costly is failure, how often do we validate it, how stable is the workflow, and what is the cheapest reliable layer for the check?