Using whatever format you want (spreadsheet, notepad, stickies) write down the things you want to get done, say, this month. That way, when you sit down to write songs, record music, email a music industry pro, or whatever, you know exactly what you need to do next. Plus, as you cross things off the list, it’s a little encouragement that you’re making progress.
Okay, how about A? The interval between F and A, called a major third, is the same as the one between C and E. So we can go up a major third from F by multiplying 4/3 by 5/4 to get an A at 5/3 Hz. Alternatively, A is a perfect fifth above D, so we could just as easily multiply 9/8 by 3/2 to get… uh oh… 27/16 Hz. This is a problem. While 5/3 and 27/16 are pretty close to each other, they are not the same. Which one of these should we use? We’d ideally want the interval between D and A to be a perfect fifth (a multiple of 3/2), but if A is at 5/3 Hz, then it’ll clash pretty horribly with D at 9/8 Hz. On the other hand, we’d expect the interval between A to E to be a perfect fifth too. But if we go up a fifth from 27/16 Hz, we get 81/32 Hz, and if we move that down an octave to 81/64 Hz, we’ll be pretty close to E at 5/4 Hz, but not close enough.