Here is how I am implementing troupe play in On Her Majesty's Arcane Service - as a strongly recommended option, but not required. These ideas are not intrinsic to OHMAS - you can use them in any game.
Troupe play is play with each player having more than one character, serving different roles. Troupe play for OHMAS is highly recommended for long term play. There are several ways to structure Troupe play for OHMAS. Choose from the oprions below to best fit your group:
The Mission Impossible Toupe
The players each have one character in play at any given time, but the group leader selects the particular characters used in this session or story arc from two to three characters offered from each player. The characters should be different types, but roughly equivalent skill level.
The Tri-level Troupe
The players each make three characters - an older character with lots of skills, a mid-level character with moderate skills, and a young character with few skills. Groups can be mixed - with varying levels of competence - or matched - with everyone more or less equivalent.
The Teacher/Trainee Troupe
The players each make one fighter type, one Esotericist, one Warlock, etc. for the number of players in the group. Each player has one older character, the teacher. The rest of the troupe are Trainees.
The Classic Troupe
The players make two characters each - a spell-casting type and a competent warrior type. They also make a group of young trainee warriors. Each competent warrior is paired with a spell-caster played by a different player, The trainee warriors are miscellaneously played by anyone who wants to as an additional character.
The Battle Troupe
Each player makes a group commander, and the other players each make a character to serve under each leader. The follower characters should be lower powered than the commander. This would probably work best with smaller groups.