I created this tutorial using my sequencer software of choice, Steinberg's Cubase 5, but it should be very easy to translate this technique into the sequencer of your choice (e.g. FL Studio, Reason, Logic, Alberton, etc). The VST instruments I use are Groove Agent ONE (native Cubase instrument) for drums, reFX Nexus2 for a selection of pads, basses, and leads; reFX VanGuard for virtual analog leads (great for transformations using cutoff and resonance filtering). As with the sequencer any VST instrument can be used in a similar fashion.
Layering is basically playing certain notes with multiple layers of instruments to give it a euphoric and atmospheric character. I can sometimes play the same set of notes with up to 4 instruments simultaneously, as seen in the tutorial. It may take some practice to not having it all resulting in a big aural mess - but with some trial and error you'll learn what works and what doesn't.
In the tutorial I first play a section from my recently released track "Imaginary Friend" and then I spend most of the tutorial playing each instrument individually and then together with previously covered instruments in order to position its place in the overall mix. The instruments covered are drums (percussion), main bass line, secondary rolling bass line, a dreamlike pad, two supporting and transforming leads, and 4 melodic layers of leads.
You can view the tutorial here (it's in HD (high definition)) so you might want to view it on YouTube in SD if it doesn't play smoothly:
Feel free to comment the tutorial, subscribe to my YouTube channel, and listen to all of my music (7 hours+) at my official site. You may also request a tutorial topic if you hear something in my music that you wonder about. Also, I'll be archiving all my tutorials HEREif you want to find out more.