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Simon's video is currently in real time. It's more demanding because they had technical challenges to overcome.
I recommend the second tutorial that you posted. However, instead of a thin gradient, use a tileable texture that looks more like smoke. You can even use two trails with the same sound that are slightly offset so that you have a more "fancy" feeling.
Creating textures is one of the many hats a vfx artist must wear. How you do it is up to you. Some use substance, others manipulate the picture, and others draw it by hand (or all, depending on the task).
Also: learning through action. Give it a try and if you run into a barrier come back and ask for advice again