Start basic commands. Train for about 5 minutes per day and slowy increase the training time. Teach one command at a time. Once they master one command, move onto another command.
Number one command is sit. Teach the pup to sit, by placing a treat in front of his head and move it to the back causing him to sit to get the treat. When the pup sits, tell them good sit and give them the treat.
Second command should be "focus/look" This will help you tremendously when the pup is over 100 lbs. Put the pup into sit. With a treat in your hand (let the pup smell it), put the treat up to your eyes and tell the pup to look or focus. They may only do this for about 1-2 seconds. As soon as they look at your eyes, tell them good look or good focus and give the treat. Some mastiffs (DDBs generally) do not like to look anyone in the eyes for long because that means a challenge to them. Titan is up to 35 seconds of looking at me.
Other commands are stay, come, leave it and drop it.
When you are training and when the pup does not do as you ask, then tell him no no no and redirect back to command in a normal voice. The only time a stern and somewhat loud NO should be used is when they are doing something that can cause harm to themselves or others.
For example, when I'm doing the look at me training with Titan. He will look at me and then his eyes will move to the left or right. I say, "no no no, look at me" and he returns to the look to my eyes.
When they do what you want them to do, get all giddy and excited and say, "Yes, good look!" I clap, giggle, and sometimes do a little dance. My dog looks at me like, really woman?
Mastiffs can be extremely stubborn and if you get frustrated with them, they will shut down. Mastiffs do not do well with yelling or hitting. Hitting can result in some unwanted mastiff behavior meaning fear aggression, which equals biting.
we have Cas,his 3.5months. We go to training classes and all he wants to do is play with the other dogs! Yet when we're at home he does everything during training sessions. 
