Magpul's Art of the Dynamic Handgun is the best video out there. In terms of sheer training and information, it can't be beat.
Otherwise, actual professionally training is a good way to go. I encourage everyone to go out and get formal training at least once, so that they know what is out there.
DinanTronics Stage 1 F30 328i M Sport
Dinan 20" Black Performance Wheels
Gunfighter Training Development and Evaluation
AR15/AR10 Armorer/Advanced Armorer
Gunfighter Training YouTube Channel