Cloned from Clone of Gahalad's Main cube

First of all, there are no infinite combos in the cube. The cube is built around the 10 guilds
There are 3 manafixing lands per guild and the Landscapes, but no (rare) fetchlands, so going 3+ colours is possible, but you have to pick the fixing quite high. Also most of the 2 coloured decks have incentives to splash another colour for a few cards. This usually creates a version of the deck, that is a bit slower, but has more power to offer.

The themes of the guilds are as follows:

Azorius : Control
Use counterspells and carddraw from blue with efficient removal and mass removal from white to stabilise and finish the opponent with a big threat like Ezrim. This Deck has incentives to splash black for more removal.

You can also draft this color combination as a tempo deck, relying heavily on disrupting creatures and counter spells

Simic : Ramp
Use greens ramp to get going faster and slam big haymakers to win the game. The blue mostly adds consistency with card draw/selection and it gives you access to utility creatures and more top end options. This deck can splash very easily to other colours for more finishers.

Dimir : self discard (looting)
Use looters to draw and discard cards and payoffs, that grant you bonuses for either drawing additional cards or for discarding cards. These payoffs are also triggered by cycling cards. This deck can splash red for cards like inti, seneschal of the sun or faithless looting

Orzhov :small creatures matter and recursion
Gain card advantage by recurring and buffing your small creatures (power 2 or less; mana value less than 3). Most payoffs for power 2 or less only care about the power outside of the battlefield, so they still work with anthem effects.

Rakdos sacrifice
At base, this is an aggro deck, that wants to kill fast with recursive threats. Then on top to finish the game, you use a suite of sacrifice synergies to finish the opponent. Additionally you get "threaten" effects to bolster the strategy for very cheap "steal and sac" synergies.

Gruul : zoo/ atarka red
This deck is very aggressive and wants to bash heads in with efficient, cheap creatures like experiment one, voltaic brawler and goblin rabblemaster. Your top end is usually at 4 Mana with bloodbraid elf and ulvenwald oddity

Boros : go wide Aggro:
This is deck wants to go wide and then buff all your creatures with anthems and Bushwhacker effects.

Izzet : Spells matter.
This deck is very explosive. You either go wide with young pyromancer and friends or go tall with the prowess creatures. This deck depends on cheap instants and sorceries to trigger your enablers. There is a version of this deck, that splashes white for Leonin Lightscribe or monastery mentor

Selesnya : blink/flicker
This deck abuses enter the battlefield effects of creatures and triggers them again when exiling it and bringing it back. You haven't truly lived until you flickered a thragtusk the same turn you play it. This deck can splash either blue or black for more EtB effects.

Golgari : Creature toolbox:
This is by far the most difficult deck to draft in the cube. This deck is a slow midrange deck, that wants to tutor up the exact creatures it needs at the moment with spells like green sun's zenith, the huntsman's redemption or fiend artisan. The second way of tutoring is by using birthing pod (and Vivien on the Hunt). This puts your deck under a tight deck building restriction and you have to remember your curve (and what cards you already played and can't find anymore), but if you manage this you have a very versatile deck, that can grind through almost everything. Creatures with enter the battlefield effects or dies trigger work especially well in this. One additional note: you can find grist, the hunger tide from any Creature tutor, that finds a 3 MV creature or unearth. This deck can splash any color for additional value creatures.

Sultai Selfmill
Use self mill and discard outlets to fill your graveyard to boost your creatures and use it for delve and recursion