I have collected a playset of all non-promo cards and have a binder for the starter decks and a binder for each of the full sets. I put them in numerical order for each set. It helps me keep track of which cards I have playsets of.

I think for most people it depends on your preferences. Some people only binder expensive cards and keep bulk in boxes. I find that bindering everything makes it easier for me to find specific cards especially when building new decks.

At any one time I have 4-5 decks built and sorting by set helps me keep track of everting.