When to use 1 vs. 2 vs. 3-stage build?

I'm relatively new to using starter and apologize if this is a repeat question.  There's so much knowledge to absorb here and in my books.  Mine is now about 6 weeks old (Debra Wink's).   I'm unsure about how many builds to do and why?  Is it based on how long the starter has been in the fridge between feedings (usually a week or less), desired taste, style of dough (lean vs. enriched) dictating how hard it will need to work, etc.?  I keep it pretty firm like DAB, though use some to build to whatever hydration the recipe states.  TIA!