You don't build a cube with 36 cards from each guild in it. Gold cards should be really limited (well under 10% of the list). The vast majority of the cube should be mono-colored cards and colorless cards. You use a lot of interchangeable parts. You support aggro, midrange, control and combo decks in every color combination. Add enough viable archetypes so that players aren't pigeonholed into drafting specific things. Every draft experience is different if you build the cube correctly, which is why it has such amazingly high replay value.
If all your players do is pick a guild and draft it, it'll be very boring, and would grow stale very quickly.
If all your players do is pick a guild and draft it, it'll be very boring, and would grow stale very quickly.
My 630 Card Powered Cube
My Article - "Cube Design Philosophy"
My Article - "Mana Short: A study in limited resource management."
My 50th Set (P)review - Discusses my top 20 Cube cards from OTJ!