Something I've done on lighting circuits with several 3-ways, such as a kitchen/dining room/hallway/foyer type circuit, is to bring the 2-conductor supply into the first room's first 3-way switch box, run two 2-conductor cables to the second 3-way switch box, then a 2-conductor on to the next room's pair of 3-ways.
Now, I can bring the switch leg out of whichever 3-way switch's box I like, picking up the grounded conductor there, and feed the other 3-way of the pair in the other switch box, where I pigtail the hot. Obviously, the second of the two 2-conductor cables is the travelers, in which I recolor the white either red or blue with a Sharpie.