The most important thing to remember during the potty training process is to be patient. Potty training doesn't happen overnight. It will take time and there will be a lot of accidents along the way. While some parents have success potty training over a weekend (see The 3 Day Potty Training Method), others might still be trying at age 3. Sooner or later your child will get the hang of it. Keep at it and don't give up.
Be persistent and always remain positive and supportive of your child. If your child feels embarrassed or nervous about using the potty, you will not have success. Support and encourage them whether they are successful or not. In time, they will get it.