Elimination communication is basically listening to your baby's cues that are saying she has to go potty. Babies make a certain cry that is slightly different than a hunger or tired cry when they have to go. There are other signs that sometimes happen but it just takes some observation, as in diaper-free time. There are a few books on the subject as well. We read "The Diaper-free Baby" by Christine Gross-Loh to learn about more details. We found an infant sized potty that we used as well as sitting on the toilet and holding her over it or putting her between our legs as we sat on the toilet to hold her. We would make the cue "psssss" and a grunting sound each time to signal what we thought she needed to do.
We started EC when Rebecca was just 3 days old. Babies are smart. They know when they have to go potty. It is just up to us as parents to listen to their cues and respond. We noticed that she would make a distint cry when she had to go. We also went by timing as well. Generally, it is about 45 minutes after she feeds that she would have to go potty. For the first 7 months we caught most of her pees and poos during the day and evening. Night time we didn't really do EC because we would be getting out of bed multiple times in the night and it was just too exhausting.
When she started to crawl and become more active around 7 months, things began to change. She stopped telling us when she had to go potty. Sometimes we knew she had to go by her signs, but she refused to sit on the potty by arching her back and crying. We took her lead and stopped trying to take her. Since then she has gone through different seasons of either signing "potty" or walking into the bathroom and motioning to the toilet and actually going or refusing to let us take her. At 18 months old she still refused to sit on the potty/toilet for most of the time, sometimes she surprised us and told us and actually went. At 19 months we decided to have her go diaper-free except for naps and nighttime. To our amazement she now says "pee" or "poo" and we set her on the potty and she goes. There have been a few misses but it has "clicked" with her and she lets us know when she has to go. She can almost go herself, except for lifting her dress when she sits down.
In the beginning it was really rewarding to be able to communicate with a tiny baby. As she grew older it was just more frustrating than it was worth. I don't know if I will spend the time and devotion to begin this process of toilet "training" at such an early age for our future children. It could just be that she needed to be diaper-free more for her to like going on the potty. We will see what the future holds.