Potty training for cats is not that difficult. All you must do is following the classic guidelines every cat owner should do. These rules apply for most cats and actually quite easy to follow.
Keep the litter box clean
How often do you scoop the dirty litter? Once a day? Once in two days? How often do you flush your toilet? Well, you don’t need to clean it after every use by the cat, but at least do it twice a day. I clean my cats litter every morning and evening, before and after work. Make sure the box is large enough so your cats always have enough space.
Have enough boxes
It is always useful to have more litter boxes. Your cat might feel that one box is too full, so she decide to look for another place. Alex from http://www.heartministryga.org/ reviews many popular litter boxes. I love his insights because he is such a passionate cat-lover.