Art by Alan Pollack[x] Singleton, gates are the exception.
[x] Hybrid-mana, tricolor decks welcomed.
[x] Ravnica guilds, clear synergy via signpost cards.
[x] Watermarked cards, equal representation across guilds.
Azorius -> Control (detain+flyers)
Dimir -> Control (surveil+Flyers)
Rakdos -> Aggro (unleash+spectacle)
Gruul -> Midrange (riot)
Selesnya -> Combo (tokens+populate)
Orzhov -> Combo (afterlife+aristocrats)
Izzet -> Combo (spells+spellmatters)
Golgari -> Midrange (undergrowth)
Boros -> Aggro (battalion+mentor)
Simic -> Midrange (evolve+adapt)
I thought about that when writing!
I keep my color and guild sections even. For me, it's easy to keep the guilds equally represented and relatively balanced. However, the impact on draft and gameplay of going +1 or -1 card in a guild is marginal - even less so going +3 or -3 in a mono color. You could make a strong design / choice argument for doing or not doing this.
I do cheat with some cards, especially in mono-color. If I want to slot another land or colorless card in, I might see Phyrexian Metamorph in my colorless section and go "hm...you're a blue card now."