I want to potty train much earlier than is common, when my son is 12 to 14 months old. What's the best way to go about it?
Many parents find that the "elimination communication" method, also known as 'natural infant hygene' is a simple approach. It is important to clarify that this approach is not 'potty training'. Rather, it is a two-way communication. Children know how to potty when they come out of the womb, and most will let you know.
The basic principle of this approach is that children communicate when they need to go, and that the most difficult part of toilet training is un-training the diaper training. Typically, a parent waits for a child to finish pooping and then changes the diaper. This trains the child to poop in their diapers. But the fact that children pee when their diaper comes off may be evidence that they would prefer not to pee and poop on themselves.
The 'elimination communication' approach starts when the child makes a pooping face - often when feeding early on. The parent removes the diapers and holds the child over a toilet. There are toilets that a 3 month old can use (figure 1). When the child poops/pees, the parent makes a 'cue' sound ('sss' = pee; 'mooo' = poo). The child learns to associate the sound with eliminating and will eventually learn to poop/pee when the sound is made.
This approach focuses on communicating with the child and allowing them to put their waste in a receptacle. It is not important to catch all of the poops and pees, but it does reduce the number of wet or poopy diapers that that need to be purchased, changed, and discarded or washed. And when the child is old enough to go to the toilet on their own, it will seem natural to them it will not as necessary to train.
Unless you have a parent who is with the child 24/7 and can constantly and consistently monitor the child's facial expressions and movements, I would highly recommend not wasting your time. In most modern societies today, this is quite an ambitious and futile goal. If you can't be utterly consistent with it, then you end up confusing your child which makes it delay future potty training. Wait until they're around 3 years old and start trying then.
Not to say it can't be done, but I make my argument after ambitiously trying with 2 of our 5 kids to start potty training too early, which backfired on us.
Update: I don't quite understand the down vote since there was no comment left, but after scanning the "Super Nanny" book, Jo Frost gives pretty much the same advice about not starting too early.
Three parts to toilet training: recognizing "the feeling" (aka readiness), knowing where to go, and getting undressed. The hard part is getting them to recognize "the feeling" when they have to go. For young children, they say it's more about training the parents. Be the scientist and keep notes about when they drink and when they go. Then put them on the toilet at regular intervals with a book and give LOTS of praise when you hear a noise.
Knowing where to go can be done by modeling with a teddy. Have your child teach the teddy where to go at the same time as they are learning. Play-acting with a toy helps instill the routine.
Finally, getting undressed is a big hassle for really young children (an sometimes their parents too)! If you want them to be completely independent dress them in long t-shirts. Elastic-waist pants are good.
At 12 to 14 months, elimination communication (EC) is still definitely an alternative to 100% diaper dependence and poopy diapers. EC is not potty training - it's just opening up to the idea that same with feeding and sleeping, your baby is actually trying to communicate with you that he or she needs to go. It's not about performance. Do it when you can. We EC'ed our boy since birth and we've only had to change a handful of poopy diapers since. At this age, babies are more mobile and have probably lost the sensitivity to wetness, so a modified EC approach would work best. Don't skip the basics! Spend some diaper-free observation time learning his or her body's rhythms and any signals (grunt, fussiness, suddenly stopping play and staring, etc). A good idea would be to switch to cloth diapers so that both you and your baby can tell when your little one is wet. Get your baby used to sitting on the potty by sitting him on it while he's still wearing his diaper as a start, then remove the diaper later on in the process. My website, EC Simplified is a practical resource for EC, you can start with