I started PT my DS at 17MO now at 19MO I'm having major success! A few things I've learned and hopefully can help you too.
1. Going poo or pee is NOT a reward! How would you like a sticker everytime you went to the bathroom? It teaches LO's that PT is a game rather then a NATURAL function of life. Which leads to regression once the stickers and praise stops. "If mommy doesn't care anymore why should I."
2. Approach PTing as matter of fact. Introduce your LO to the potty sit him/her down. Explain that is where you go pee/poo. Don't force 10 mins to beyond sitting. I've done it and it doesn't teach them anything. I know the theory is the wait for that "perfect accident." Good luck waiting for it!!" :)
3. The infamous "wait till their ready." It's not when they are ready but when you are. Read through all the EC'ng threads you will quickly discover it doesn't exist. From this board I was told to give up that my DS is too young. I'm happy that I didn't listen to those naysayers and persisted! Don't ask your dr, friend, family do it when you feel you are ready to tackle it.
4. It is messy and will be till you become consistent at their cues. Invest in carpet cleaner and stock up on paper towels.
5. Lots and lots and lots of Naked time!! Trust me I know how daunting the idea is to run after your LO, hope and pray they don't have accidents on the floor. But they will and it's vital to help you understand their cues. Once you pick up on when they will go it's SOOO much easier to put them on the potty. Many here ask when will I know a few things: start writing down meal times, nap time and accidents. That will give you a general idea. Pay attention to facial expressions my DS has a faraway look. Also their behavior they hide when they are going.
6. Clear your bathroom floor of rugs, objects or any possible distraction. By accident I learned that my DS will go to the washroom on cue if he's in the bathroom by himself. Put your LO in the washroom and close the door behind them and let them know you are sitting outside the door. It would surprise you how willing they are to go. Associating the potty is not hard ask them to sit on their potty and pee/poo.
7. Have lots of patience! After an accident happens say "Accidents happen but you go pee/poo in the potty."