I make a 4 liter starter, cold crash it, decant, and then step it up with another 4 liters. I then cold crash it again, decant, and divide out the slurry into 5 jars to have 5 healthy starters for future use and pitch the remainder into my fermentor (I'll use these starters up to a year or more from this step). I will then repitch onto the yeast cake up to three times (just depends on what is on my brewing schedule). This gives me up to 18 brew sessions from a single yeast packet. I should also note that nothing comes into contact with my yeast starters that hasn't been autoclaved. Also, I do all step up work and transfers in front of a laminar flow hood.
This is so much easier than what I used to do 20 years ago when good yeast was harder to come by. I used to keep slants, and step up from single colonies....that was a real PITA!