[scootermojo]

I usually start out with the current MLB setup then sim a few years followed by the following expansion teams:

Las Vegas Aces
Richmond Virginians

Then I'll sim a few more seasons (at least 4) and add the following teams via expansion:

Portland Beavers
Oklahoma City Jacks

I'll sim at least 10 or more seasons after that then do a massive expansion by adding at least 4 teams at once and do a realignment of the leagues and divisions to the point where I have 4 divisions in each league composed of at least 4-5 teams each.

Some of the teams I've added in the past:
Montreal Barons
Vancouver Emeralds
Nashville Outlaws
Louisville Sluggers
Alabama Dixies
New Orleans Jazz
Memphis Pilots
Charlotte Knights

Usually my goal is to get up to at least 40 teams, 4 divisions in each league, 5 teams in each division so only division winners make the playoffs and I eliminate the Wild Cards and Wild Card rounds. I've never really gotten any farther than that.