Response to Laureat:
I don't intend to say that it's wrong to watch tutorials, or that it's wrong to ask on forums. Not at all. But don't let that dominate your limited creative time. Don't spend more time studying than doing. I know from experience that it's easy to get paralyzed by research, and then I never create what I am spending all this time learning to create.
It's all about finding the balance that's right for you. My sweet spot is about 15% research and 85% creating.
Response to James:
I think purely copying tracks is a useful exercise for the times when you feel stuck or don't know what to do next. For example, I made a clone of a Calvin Harris song in my DAW. Just the chorus, actually, and without vocals. But in doing that, I learned a lot about synth design, I learned that his balance of instruments is significantly different than what I would otherwise choose, and that just about every element is swimming in more reverb than you'd expect. I learned things, and it gave me ideas. Ideas on how to be more like Calvin Harris, but also ideas on how I can be different, how I can go in the opposite direction.
Did I publish my clone song? Of course not. Do I spend all my time making clones? Of course not. But it is a nice teaching tool that is way more hands-on and mentally stimulating than listening to someone drone in a YouTube tutorial. There is a time and a place for it. But, as above, activities like this shouldn't take up too much of one's creative time.
For the original poster:
Every track needs a place to start. Sometimes I start by finding drum sounds I like, arranging them how I think they sound best, determining the tempo of my own performance, then recording them. Once the percussion is in place, I see what other instruments fit. Synth pad? Synth lead? Electric piano? Bass?
Other times, I start with a melodic idea I had while driving. Which instrument best fits the melody? What is the tempo I imagined? Get it down as quickly as possible, then see what kind of percussion adds to it, what kind of bassline enhances it, etc.
Other times, I just scroll through presets in a virtual instrument I don't know very well. Maybe a synth, maybe an electric piano, etc. When I find a preset I like, how does it ask to be played? Once I play it that way, what tempo fits? Set the tempo, record it. Now what other instruments support it? What style of drums and what style of bass?
Everybody needs a place to start. Maybe I'm unusual in that I have multiple? I'm not sure. U2 has one member that throws together hastily made guitar and drum parts as an audible scratch-pad. Then the rest of the band chooses which ideas they like in order to turn them into songs, and which ideas get thrown in the trash. I imagine that nearly all Victor Wooten songs start with him messing around on the bass, then a song is built around that foundation. Because bass is what he does. Probably a lot of rap songs start with percussion. Figure out where you need to start for your genre and your process.
Do you find it hard to start with a bassline? So do I. Try starting from a different place, then add the bass that fits using the notes that fit.
But if bass is central to your genre, don't wait too long. Make it first, or make it second, while the bass still has a chance to determine the sound of all the instruments that follow.