One of the best ways to have success with IPT is to cue your baby consistently. Whenever you take your baby potty, communicate what you want them to do by making the appropriate sound. Use ssst for pee, and a grunt for poop. This helps your baby know exactly what you're wanting. You can also try blowing on the top of the baby's head, which is what the Eskimos do. It helps our daughter relax, especially when we're having to use an unfamiliar potty place. I have found that incorporating sign language is also enormously helpful.
The sign for poop can be made by giving the thumbs up sign with your right hand, and then grabbing your right thumb with your left hand and pulling it up and off of the right thumb. We never had much luck with the sign for pee, but our son did do the sign for toilet. Simply put your right thumb in between the index and middle fingers of your closed right fist, and then rock your fist back and forth. Use these signs right before, during, or after going to the potty or pooping. You can also say the word as you're signing it. Most importantly, do the sign when your baby is paying attention to you.