Clear all low diffs on specific maps and then concentrate on reducing Miss to gain PP, it is very crucial to improve advanced skills to play higher diff maps in an effective way. If my performance is unstabilized, I'll be willing to play converted maps from EZ to EX diffs to farm the ranked score.
Keep a balance between gaining PP from specific maps and enjoying the random pattern from converted maps.
I created collections and sorted them out by *Miss*, rather than *star rate. Star rates can be variable by updating the SR system, but how many I missed can reflect my skills directly.