I make up my songs but my lack of ability to play instruments or translate them into any form of musical notation prevents me from making anything of them.
So instead I dick around with Fl studio. Generally in C Major, because in FL's piano roll all instances of C have a giant black line beneath them, and its easy to just put notes on the white keys.
I also use mainly 4/4 time because though I like interesting time signatures they can be a pain in the ass to make sometimes.
I generally start with drums and eventually decide something else needs adding.
Here are songs I've made which adhere to those rules:
EDIT: I ACCEPT NO RESPONSIBILITY FOR ANY CONSEQUENCES OF LISTENING TO THE FOLLOWING PIECES
Short, sweet, with silly pitch bending antics:
http://soundcloud.com/jem33333/wheoowheoo
A more laid back tune:
http://soundcloud.com/jem33333/mellow
Some funky stuff going on here, found the sx synth zomg:
http://soundcloud.com/jem33333/funky-stuff
And here is a song which does not comply with the above rules. It uses an Arabic Scale (mostly C, but with an occasional key change), a wide variety of time signatures, alternating every now and then at at one point using three overlapping signatures with little purpose or added effect. Mostly its 5/4.
Also it starts with a Harpsichord. <3 Harpsichord
http://soundcloud.com/jem33333/arabian54
best bit is probably from about 4:13 when the Harpsichord solo begins.
edit:
Oh also I've been listening to some of the other stuff in the thread. There's some cool stuff! I like MK's jazzy thing (5/4 time ftw)
BlackwaterPark's stuff is pretty cool too. For Hannah is rather nice.
Alch you have a nice voice, but your stuff all sounds fairly similar and (imo) a tad boring. I certainly wouldn't say it's bad though.