There are some great Youtube channels that give insights into martial arts and CMA, and even though I’ve never studied Wing Chun (only Taichi and Taekkyon) the guy really gives great insights into a traditional martial art. I often watch it not because I’m going to train in Wing Chun, but because it teachers the importance of understanding your chosen art.
One of the problems with traditional Chinese arts is that we can get too focused on just forms. When I was in China and got a little enthusiastic buying up VCDs on different styles -Hongquan, Wing Chun, 7 Star Parying Mantis, Nan Chuan, etc etc… And they all teach forms, and may give a few basic applications but nothing more. Learning the forms without understanding the principles is almost next to useless, and your prone to getting into bad habits that will hamper what could otherwise be an effective art.
The ChinaBoxer videos are a great example of this for Wing Chun practitioners as he instructs on important principles -keeping the 70 degree angle, attacking the centre, keeping structure from the heels up to the hands, focusing on the elbow and not the fist etc… I’d love to find indepth vids of taichi as good as these! (Sadly Erle Montaigue is not longer with us…)