Looks good, just a little tip coming from someone who was trained as a hair stylist, spend the money on hair cutting scissors. Even cheap ones since you're using them on fake hair. Kitchen scissors or fabric scissors don't have the same quality and precision. [link] is a pretty good pair for a VERY reasonable price. I got my scissors for over a hundred dollars, those are the ones i use on real hair. For my wig scissors I use a slightly cheaper pair that I got while I was apprenticing.
I am a hairdresser/hairstylist so I know this. I have not noticed any big difference between using a more expensive hair scissor and a cheep, smaller kitchen scissor. I just find it unnecessary for people with a low budget to go out of their way to buy a scissor they cant use properly anyway.
This tutorial is actually quite useful. When I saw the thumbnail, I was worried you were going to use the scissors horizontally (which is something you must never do with things like this!), but it's actually quite useful.
I sound completely weird, but whenever I grab a bit I move up with the scissors. This makes it easier for me to choose the length of the bang, and start off with the longest bit, and the longer buts (that I've already cut) usually fall down and out of the way to allow me to cut the shorter bits. I think it works out fine, but I will most certainly try this cutting down the bang technique!
I use one pin at the top of the wig, and another down at the bottom. This is to stop the wig moving when I spike or tousle the back up a little. One pin at the top is usually enough for me!
I'm happy that you have a technique that you feel comfortable with. I manly made this tutorial because I've been asked how I cut wigs and this was the easiest way of explaining it in an understandable way.