Songwriting can be very gratifying but sometimes super frustrating. I find that you need to be able to let go a little bit and allow your intuition to guide you. My best songs were written in a quick creative burst.
Inspiration can come from a number of things, it can be an experience, a feeling, a book or an article or just the music that I am listening to at any given time. It's like, "I have to express this in my music", "wouldn't it be cool to have a song about that", or "I could do something like this", or even "I want this kind of thing in my repertoire". Also, the process is getting easier as I grow older. The general perception is that musicians do their best work when they are young and "pure", but I think this is a misconception. Knowing stuff and having some maturity to draw on is never a bad thing.
Sometimes the words come before the music, but it's mostly the other way round for me. I really enjoy playing guitar, and a lot of my musical ideas come from jamming on my instrument: a cool progression or a catchy little melody. When I find these worthwhile, I record them on my phone. About 90% of these never get any further, but if I have something really exciting, I can spend days toying around with it in my head until I can find the time to work it out properly.
One thing is important to me, though. It needs to flow. If I have to struggle with it, the result will suffer, too. There's a ton of "formats" that can be helpful if I do get stuck. Adding a breakdown or a middle part to the song's structure can have a huge impact. Sometimes, just putting in a stop can make it so much cooler. Dynamics are another thing that can make a song really stand out. That's something you hear a lot in dance music: a really quiet part to build anticipation and then the beat drops and everyone goes crazy. There's also a bunch of stuff you can do with different arrangements, but that's for another time.
I recently saw an interview with Paul McCartney, where he said that the good thing about not having any sort of recording equipment around when they were younger was that they had to finish a song in one writing session or they would just forget it. It also helps with weeding out ideas that simply aren't worth the effort. I tend to agree.
Once I have the roots of a song, I latch on to it and try to put it together as quickly as possible. If I get bogged down I better leave it alone, at least for a while.
