First, use lots of books and talk it up, making sure they understand what it means to be potty trained.
Second, you will need supplies: an empty jar, about 40-50 marbles in a different container, some training underwear (hopefully a little thicker), a potty seat of your choice (I always used the kind that have them sit right on the regular toilet and have a stool for them nearby) and a good reward idea. (We used an amusement park trip for one child, a trip to a fun and entertaining pizza place for others. Of course, you can also show and excite them about the fun new character underwear they will get to wear when they are all trained.)
Third, you prepare them by telling them that tomorrow is the day they get to stop wearing diapers.
On the big day you take off the diaper and have them try sitting on the toilet first thing in the morning. If they successfully get anything in the toilet, they get to choose and drop a marble in the empty jar. You tell them that when the jar is full, they will get to _________ (insert your chosen reward). (My rewards have ranged from going to an amusement park to a visit to Chuck E. Cheese Pizza.) If your child is not successful, you have them sit on the toilet about every 20-30 minutes and try. You don't let them put a marble in unless they get something in the toilet. I had a friend who told me she did let her kids get rewarded if they successfully farted while on the toilet. That is up to you. :D Once they have successfully gone a significant amount, you can probably wait about 45 minutes to an hour before having them try again. It is important to have them practice pulling down their own underwear, wiping, flushing, and washing hands each time they try.Offer them lots of liquids while they are first learning. Water, juice, milk, and chocolate milk are all helpful to let them feel the urge to go. It is wise to have the children wear pants over their training underwear, so that the bulk of the liquid is felt by the child when an accident happens. If you have them in pull ups, it's not much different than a diaper, so they aren't going to care. When they feel all wet and uncomfortable, that is when they really learn.
When an accident does happen, which of course it will, this is your big time to be calm and kind, but firm. You nicely have them help you clean up any mess from the accident. You take a marble out of the jar. (You do it, not them because you don't want to make it fun for them.) Then when they are all dry and changed back into fresh underwear, you have them go back to what they were doing when the accident happens. Let's say they were watching TV. You take them back to that room and have them start watching tv or doing whatever they were doing and you say, "Now, because you had an accident, we need to practice 3 times. You were watching TV, so if you are watching TV and you feel like you need to go to the potty, what should you do? You call to me, 'I need to got potty' and run into the bathroom, (you help them run to the bathroom), you pull down your pants (they do this), you sit on the toilet"...etc., right down to the flushing and washing hands.
This practicing may seem monotonous and time consuming, but it is one of the most important parts, because kids don't like it. It keeps them from playing and doing what they want to do. They will quickly figure out that it is easier just to go when they need to go and only have to do it once. That way they also get to put the marble in and can earn their reward sooner. It is good to remind them often how fun that reward will be and how good they are doing at earning it. Try to be as positive as you can be when they are successful and as calm as you can be when they are not.
With the pooping part, it is good to show them the facial expressions of pushing hard and grunting and maybe that reward for farting would even come in handy with becoming successful on the toilet. If they have a regular time of day and you see them looking like they're needing to go, get them to the potty quickly. That's one mess it is no fun at all to clean up, but we all do it. Oh, the joys of washing underwear in the toilet.
As they get further along in potty training, it is normal for children do begin to dance when they need to go to the bathroom (especially after they have experienced being wet), so watch for the signs, to help remind them. Help them get used to sitting on a regular sized toilet with your help, so they won't have a problem out in public.
When they finish putting all the marbles into the jar, or get the jar filled to the top, reward them quickly and with lots of praise and pride. It is good to keep using the practicing at least a couple times, if an accident happens, just to keep them in good habits. That is really all there is to this method. Happy potty training!
