So this could be a fun discussion for a lot of us, since creating music is fun but sometimes tedious task. It's definietly worth it though, 'coz then you create something you can be proud of and that other Newgrounders can use for their righteous flash games and movies! I'll start with a mind-dump...
Fear of the blank canvas, the enemy of all artists. Drawing inspiration is an easiest fix to this. So, what this means is that by experiences a lot of life will helps with this. Going out, exercising, hanging out with friends, like-minded individuals, or even dealing with some of life's BS like bills or stress, are a few things that elicit emotions and start stirring the brain cells for some good ideas. Hearing a dog bark inspired me to write this.
Appreciating a lot of art will help to improve literacy; so you can understand more how to express yourself and not accidentally copy someone's work. Listen to all kinds of music, admire objects or illustration, watch flash cartoons, go to the movies and watch a crappy Hollywood spam flick even. All things that help inspire and elicit ideas.
Speaking of exercise, seriously working out every other day and/or just riding a bike to places instead of driving when possible, boosts dopamine, bodily processes, and self-esteem. That'll gain you confidence, thus confidence in your work. If you sit in front of the computer to the point of a thinking headache like I do sometimes, then exercise is a fast way to get rid of it :)
Now, more specific to music. Sometimes you'll hear a melody first, or a drum beat, or something that sticks and urges you "hey, write me down somewhere!". That's great, and sometimes it'll snowball into something you can call a song and it's done in two-three hours tops. That's gratifying :D You might find you have to work a little harder though, and you might have to lay down a chord progression or a drum loop or sound effect first and think for a second "...what exactly could this express? How am I going to make this sound good? Where does this sound take me and the listener?".
The worst thing for me is being on a roll and suddenly coming to a stop because I hit something difficult. For example, when I wrote Blissful Venture , I heard/felt the beginning of that when I kissed a girl and the song practically wrote itself until I hit the middle section (1min15sec in the song). I knew I want to incorporate a D Major chord, a specific sound that conventional thinking wouldn't imagine can fit this puzzle, but if done correctly can make things interesting.It took me an hour of just staring at the computer and thinking... then it hit me. I thought "well, what if I just copied that E Major chord and just lowered it one pitch?...".
In other words, Occam's Razor. "The simplest answer is almost always the best answer". Looking deep down inside for a good idea or suggestion is difficult, which is why experiencing plenty of life, art, and love will give you internal and ethereal feelings. I like to buy knick-knacks occasionally for this very reason. An Otamatone for example, or a bouncy ball or glass figurines (like a heart, stars, or marbles). These seemingly little things can produce some ideas too.
Occasionally, you might just want to hit that writer's wall forcefully and just chuck the beginning of something new at it. For example, I Love Her I wasn't sure how to continue the song at 2:44, so I tossed my turtle up into the air and said "Let's toss some jazz in there! I don't care if was a slow ballad in A major, I'm gonna shove a Cmaj7 chord in there and see what happens!".
So if you're writing electronic music and not sure how to go about continuing a song, try just adding a new loop or sample and see where it takes you. ParagonX9's Chaoz Fantasy is a fantastic example of this. Listen closely at 50sec. 1min15 and 1min 30. He/she probably came up with those changes abruptly, thinking "ZOMG I want to include a piano part and some triangle waves, but how da fook am I gonna make that work!?". Chances are, you just sorta add it in there as a sticky note and you'll feel it come to life as you develop the idea.
Thanks for reading this epic; this outta arouse some discussion. When I finish my latest work, I'll share it here so y'all know I'm not a sham