Asalam Alaikum,
The basic belt shalwar has two main pieces, the belt and the legs.
There are two basic types of cutting for the leg. One is simple and usually takes less cloth, while the other is a bit more difficult and takes more cloth. Each has benefits and drawbacks. The simple one is much easier and involves less steps, and it has a slimmer leg(which can be a benefit or a drawback depending on how you like your shalwars to fit). The more complicated one is a bit looser because it has more cloth in the legs so while the leg is not as slim, I personally find it to be more comfortable.
When attaching the leg to the belt there are also two basic options-gathering the excess material like this-
The other option is to make nice even knife pleats like this-
InshAllah, I will shortly be posting the first of my belt shalwar tutorials. In the first tutorial I will explain how to make the simple leg belt shalwar with the gathering, and in a couple of weeks I will add the second tutorial with the wider leg and pleating.
The first tutorial will be broken up into part one and part two as it is very picture heavy.