[marginalia_nu]

I prefer an agricultural metaphor. I think interesting ideas are planted and nurtured rather than manufactured. If you seeds for interesting ideas by engaging with the thoughts of others (may be through talking or reading), make sure to sleep well and take care of your body, then you'll think interesting thoughts and if you enjoy writing like I do, most likely be inspired to write about them.

But as Ryan is suggesting, having things to write about is a side-effect or consequence of minding your "garden" (to avoid confusion, this is not a nod to Candide).