I've just started learning to craft my first set (Seducer), and it has been a really rewarding experience. Although the research takes A LONG time it's worth it. I'm able to craft gear for any level - you just mess around with the material type and how many you use to determine what level it will be like normal gear. As long as you have the motifs and appropriate stones for the style, you can craft it in any. Basically crafting a set is just like crafting any normal gear from a clothing/blacksmithing/woodworking station. The only 2 differences are:

1. You must locate and use the appropriate station (you'll find the locations on google for the set you want)
2. You must have researched the correct number of traits for each piece you want

As an example, the Seducer set requires 3 traits on the hat. They can be any traits - it does not matter. If you untick "Have knowledge" in the crafting window it will tell you how many traits you have left before it's available. Once you have the right number of traits for that piece and the right number of materials, you're good to go!

The research times will seem daunting at first, but it's well worth it in the end. I'd recommend improving your sets so you don't have to worry about crafting them so often. While it's not hard to craft, it just saves you a bit of time and resources not doing it so often.

Good luck, and enjoy!