I love your question because it is the same question I asked myself before
finally figuring out how to skip all the traditional teaching to actually play the
piano.

Answer:
Learn skills within the context of a song, layer by layer, one step at a time.
When you do this once you simply repeat for another song with different skills.
You do the exercises as you are practicing the step by step method that I present
to you. The only exercise I believe you should do is practicing the pieces of a song.
That is the most effective way to learn anything.