The process of writing music can vary depending on your approach. For me, my initial song writing process starts with a guitar riff.
Some of my music started from riffs created in all sorts of places. Whether I was playing my axe on my bed, at my computer, out camping for a weekend, etc…if I come up with a catchy melody, or a heavy chord progression, I remember it and get to recording as soon as possible.
Also, often enough, I start recording a songs intro, and let it flow from there. Any one song can take anywhere from 1 week to a couple months to complete. Especially when writers block kicks in (damn you writers block).
Once I have my catchy riff, or a nice sounding intro, the flow and layers start from there. A lot of my music has many layers to it, meaning a base of 2-3 notes then a layer of heavier guitar tracks, a layer of strings or ambient sounds, drums, bass, all sorts of plug-ins (VST’s). It’s like baking a cake only with sound and emotion.
I’ll very often start a project/track, then scrap it all together. I usually keep a piece of it in my mind, then use it when the time comes on another track. If you listen to my songs, you’ll see that they are often a collection of riffs that I try to flow into one another. Sometimes this works well, sometimes it doesn’t.
When you create your songs, you’re approach can be very different, but as long as you like it, that’s all that matters. I put pressure on myself to make something better every time I release a song, but the truth is that I’m happy with the feedback I get from the youtube community, and I shouldn’t stress myself out worrying if something is good enough to release.
Enjoy yourself, and try new things. Keep playing with tones and sounds in your DAW until you find parts you like. There’s an unlimited amount of resources on the Internet for recording music to tap into, so use it. Tutorials, lessons, tabs, and all kinds of inspiration. Listen to your youtube peers and see what they are doing, listen to their approach to recording and song structure, gain inspiration from everywhere and put it to work.