Music students often get hit with writer's block when they're trying to compose full-length pieces the first few times. They can have a very difficult time completing a song from intro to outro, even after they've spent hours staring at the page in frustration, asking themselves why today they couldn't do what seemed so easy last week.
Sometimes it's lack of background knowledge, (they simply haven't learned enough songs by other composers for a foundation to build from), other times it's a lack of basic harmony and theory, (they do not comprehend keys and harmonies). But, the biggest issue is usually how they're approaching the writing process.
Most students don't realize that songwriting is a skill, and the only way to learn a skill is to do it a lot. Just like you have to do a lot of boring scales when you're learning guitar, you have to write a lot of bad songs when you're learning songwriting. And, you need to realize that there's nothing wrong with writing bad songs. Over time bad songs get better. Then, they get great.
This all sounds very logical, but where songwriters in training will often go wrong is this: Most musicians, (who are brand new to songwriting), like to talk about their own life in their songs, and what's more important than your own feelings? Nothing! So the student slaves away on a lyric, a melody and a groove for their chords that never quite seems like a perfect representation of their inner emotions, and then they get frustrated, and soon afterward, they usually just stop.
That's writer's block. It's your own frustration with something that doesn't feel like it's good enough to finish. It's also completely detrimental to learning. Imagine stopping scale practice because you have a note here or there that you feel sounds bad. No one would ever learn an instrument if they practiced that way.
In songwriting, "doing your scales" means writing a lot of songs. And, this means you write for Quantity over Quality. Don't spend a month on a lyric. It might make the song better, but it won't make you a better songwriter. Spend a month writing one song a day instead. Hone your skill over the course of a lot of mediocre songs. After a while, your average will go up, and your worst song by day 300 will be better than your best song by day 10.
Which brings us back to writer's block. How can you write a song a day if you're stuck on a lyric, chord, melody or groove because it's not the perfect representation of your own life?
Solution: Don't write about your own life! Don't write for your own artist project, but write for your cousin who can't hold a tune! The less you care, the easier it is to finish up the song and move on. This is doing your scales. Spend less time writing more songs. Give yourself a deadline, (like four hours), and just figure it out.
However, you also need to remember: in order to become a master at anything, you will need to spend at least 10,000 hours doing it.On average, this means approx. 15 years for most players composing about 2.0 hrs. a day. Yes, fifteen-years. Now, get to work!