Step 1. Relax and enjoy a rare moment of sunshine whilst eating lunch in the park, feel those creative juices start to flow...
Step 2. Gather round and have a bit of a sing song. Some people call this a "jam" although this implies that you know what you're doing, we usually don't.
Step 3. Record a demo and listen to it. A lot. Over and over again, until you're sick of it. At this point it usually sounds pretty good to anyone else.
Step 4. Catch 40 winks, safe in the knowledge that another successful days work is done. Next day, repeat steps 1 to 3.
For proof that my methods work, please surf on over here... and listen to "The Fall of '91" and "Dance With Me"