1. A dog!
2. An area in which to practice where it is free from distractions when you are first training your dog. As you and your dog master commands, you will want to move to areas with more distractions, such as outdoors, to continue improving your dog's ability to focus on you and the commands.
3. Treats or a toy as rewards. Figure out what works for you and your dog. Some dogs are very food driven, and some dogs prefer toys and play as their reward. Additionally, consider the size of treats you use during training! Treats that are too large fill a dog up quickly, so seek out small treats for training.
4. A short leash, and a longer training leash for distance work.
5. Realistic expectations!
Don't expect to get it done on the first few tries. Some commands take a lot of time to teach and perfect.
Try to make training sessions about 15 minutes long at the most.
There will be times when both you and your dog are frustrated. When struggling with a certain command, simply move on to another or better known command. Come back to the one you are struggling with later.
ALWAYS end training on a positive note. This keeps training sessions fun for you and your pet. Next time, your dog will be excited when it is time to practice!