Boxing lesson 5 : Combination practice.
Jab 5 times.
Jab - Punch 5 times.
Jab - Punch - Left cut 5 times.
Mike Rashid also talks about practicing 20 mins in front of the mirror. It's called "Shadow Boxing" - watching yourself, to make sure the movements are right.
And lastly it all become muscle memory. You don't need to think what to do.