As with every set, the Set Design team puts together a list of the main draft archetypes. Normally, we default to the ten two-color pairs, and LTR doesn't deviate from that. Here's what each color pair is up to:
(Note: I'm going to use "typal" a few times in this section. That's an internal way that we refer to cards that care about creature type.)

White-Blue: This archetype is a midrange deck often using evasion as the win condition with a "draw a second card" theme.

Blue-Black: This archetype is a controlling amass deck. It has a milling aspect, allowing you to mill yourself for gain or the opponent to win. It also has a light Human typal element.

Black-Red: This archetype is an aggressive amass deck. It has a sacrifice component as well as an Orc and Goblin (as a batch) typal element.

Red-Green: This archetype is a ramp "power matters" deck pairing larger red creatures with green Treefolk. It also dips into the wild creature element of the set.

Green-White: This archetype is an aggressive Hobbit deck that makes use of Food tokens.

White-Black: This archetype is a "legendary creatures matter" deck that makes use of the Ring tempts you mechanic. It has more legendary creatures and a sacrifice component. The Ring helps you splash a bit more than other archetypes.

Blue-Red: This archetype leans on a Wizards theme and has an "instants and sorceries matter" center. It's a control archetype that rewards you for casting a lot of spells.

Black-Green: This archetype has a life and death theme. It sacrifices and regrows cards. It's the other archetype that makes major use of Food tokens.

Red-White: This archetype is a go-wide Humans deck. It ranges from aggro to midrange depending on what cards you draft.

Green-Blue: This archetype is a tempo Elf deck. It has some Elf typal elements and rewards for scrying.