This data is collected from the articles deck lists in EDH Chamber.
Dragons, alongside Goblins, are reds primary creature types. Dragons are reds strongest creatures and most of the expansions have some kind of red dragon in them. As dragons are expensive to cast, dragon tribal decks run multiple cost reduction effects and have ways to cheat the expensive dragons on the battlefield.
Mono blue has multiple ways to clone own or opponents permanents. The gameplay changes effectively, when you get to play your opponents biggest threats, too and clone decks can lead to some very weird and interesting situations.
Artifact decks aim to interact and gain advantage with own artifacts by copying them, turning them into creatures and simply create new artifacts as tokens. Artifact decks are very popular and they have multiple infinite loops.
Cantrips are spells with a draw effect on them. Cantrip decks are often instant and sorcery spell slinger decks and aim to cast as many cantrips as possible and creating value from the cast triggers.
Combo decks are control heavy decks, running a heavy amount of card draw or tutors. If the decks get to assemble the combo pieces the game often ends in an infinite combo.
Elves are greens primary creature type since the beginning. Elf decks run a huge amount elf mana dorks and the are able to produce infinite and close-to-infinite amounts of mana, as the cards mana output increases with the amount of elves controlled. Elf tribals are combat focused.
Milling in mono blue can be done in two clear ways: self-mill or regular mill. In self-mill, blue usually tries to find some kind of an infinite loop piece and retrieve it from the graveyard or run the Thassa's Oracle or Laboratory Maniac combo. In the regular mill the goal is to mill opponents whole libraries and win by having an opponent draw from an empty library.