Since I primarily grow from regular seeds, I don't like to commit a whole 3 gallon pot to what might end up a male, so I regularly transplant. I've tried several different sized small pots and finally settled on 1/2 gallon juice containers. At approximately 4" square and 7" high they are big enough for the first 3 - 3 1/2 weeks or until they sex. Then the females are transplanted to their final pots. Within 24 - 36 hours they are back to growing normally. I like starting in smaller containers for another reason as well. They dry out faster, allowing me to water/feed more. The Pro Mix BX I use to start them only contains starter nutrients which are used up in 1-2 weeks. I'm usually able to give them a mild, 1/8 strength feeding around day 6 or 7, and again every 4-5 days.
There is also what is called the Tiered Method. Take 2 party cups, 32 oz. being a good size. Cut the bottom out of one and on the second one, poke some drainage holes in the bottom. Place the one without a bottom inside the one with the drainage holes, fill it with soil and start your seeds in it. When it's time to transplant simply remove the outer cup and "plant" the other cup half way deep in your final pot. The roots will grow out the bottom of the cup and spread into the soil of the new pot.