no time like the present and the sooner the better
Some tips I learned along the way, only teach one command at a time. When they get the command 9 times out of 10 times you ask them, add the next one or go outside and work on the command with the distraction of being outside. Work in small sessions 10-15 minutes at a time, a few times a day. When you ask your dog to Sit your dog should sit. When you teach your dog to come and he knows what come means, do not call your dog if you aren't prepared to go get him and make him come. Repeating commands over and over and over gives the dog the impression he can do what you ask when HE wants not when you command it. Not little baby puppies but once your dog gets the trick 9 out of 10 times, they know what you are asking and you shouldn't let them decide when they want to do it
When you teach your dog to sit, and he knows sit, and you ask and get ignored, he needs to sit. Hope that makes sense, best advice I was given. Now I cant stand when I see people say "sit. dog sit. Sit dog. I said SIT dog. DOG I SAID SIT!!!" lol so bad for your dog and your relationship lol.