When caring for pets, I try to put myself in their position. How would I like to be treated if I were a pet? A nice scratch behind the ear and under the chin every once in a while. Take a jog in my plastic ball on the floor. Treats and cat nip. A nice game of tug-o-war. An extra cricket in my cage. A ride on your shoulder while I sing in your ear, etc.
It is probably assumed that one of the biggest factors in keeping your pets happy and healthy is to provide them with safe, clean living conditions. Just like humans, animals need fresh air, water (this includes water for fish as well, not just drinking water for other pets), food, bedding, and litter several times a day and/or week. If you have a dog chained up outside (which I hope the dog is not chained up all of the time, as animals need lots of exercise and interaction as well), it is ideal to move the chain to another spot every few weeks. When a dog is chained up in the same place all of the time, it usually becomes nothing but dirt in that spot, which then becomes mud when it rains. Would you want to live in a mudhole all of the time? Also, because the grass is gone in that spot, it is not a very ideal spot for the dog to relieve itself.
As mentioned above, it is a great idea to allow your pets a time and place for plenty of exercise and interaction. If your pet is not threatening (such as biting or scratching), take time to hold, pet, and/or run around and interact with your pet. Constant neglect has the same effect on animals as it does on humans. Be kind and gentle when handling pets and remember to always wash your hands before and after any handling.
I also strongly advise everyone to ‘Adopt, Don’t Shop’ when looking for new animal additions to your household. :]