Overarching themes

• Man-Lands. Simic is the best at this. Only Red has land-hate. Most removal is sorcery-speed.
• Types Matter. Each major card type has an archetype supporting it. Golgari has the most card-type payoffs (e.g. Tarmogoyf). Legendary creatures, enchantment creatures, land creatures, etc. matter.
• Delirium and Graveyard is a resource. Regrowth, Delve, Reanimation effects are common. Grave hate is limited.

Archetypes Land based Tech

Mutate Sea-Dasher Octopus onto a man-land.
Activate Mishra's Factory. Tap Baba Lysaga, Night Witch to sacrifice it and reap the benefits while only sacrificing one permanent.
Turn Slumbering Waterways into a land with many keywords.
Custom lands support equipments and auras very well.
Cast Cleansing Wildfire on your own Silverbluff Bridge to ramp and cantrip.
Discard Madlands.
Both Legendary Lands (The Shire) as well as Artifact Lands (Vault of Whispers) synergise with Banish to Another Universe and Displaced Dinosaurs.
Enchant a land with a Rune of Flight the turn before it becomes a creature.
Sigarda's Aid + Inkmoth Nexus + Colossus Hammer = 10 poison counters

Misc. math & stats

120 lands.
30 two-color cards (not counting split or hybrid cards)
10 three-color legends
25 colorless cards (which includes phyrexian spells like Gitaxian Probe)
35 cards of each color

Land Balance

Lands in archetypes:
wants artifact-lands
wants sacrifice-lands
wants legendary lands
Ideally (we're not there yet) these three colors will have access to the same quantity of these kinds of lands.

wants lands that have 2 or more types in the GY