To be honest, many times for me, it's 'what's on sale? and what do i have on hand?', and perhaps more importantly, what was the last great restaurant meal I had, and what would I do differently? And, if I'm cooking something savory, what pairs well with it? Sometimes I struggle with a fresh side dish, and then I really have to get creative!
I tend to keep a pantry stocked with nuts, mole, curries, common dried herbs, dried beans (navy, black, red), lots of yeast and flour, and, yes, I do use Pillsbury! It's what my mom and grandmother used, and it's what I use. Shameless plug, I know, but (especially lately) I've been on a kick to recreate breads that I have in sandwhich shops and restaurants for home. Flat breads (great for pizzas and sandwhiches- forget paying Subway!), homemade Italian bread (makes AWESOME garlic bread at a fraction of the cost), and so on. And, I tend to make my own pastas as well. Fresh pasta takes very little time, and tastes amazing as we all know.
Seasonality of fruits and veggies comes in to play as well, since I love to dress up dinner with great sauces, like blackberry-chipotle, or red wine and cherries (great on steaks!).
And, I share ideas with others as well (see my blog, http://michaels-killer-recipes.blogspot.com/ ) to get new ideas, especially if they are more ethnic in nature (homemade pilaf, cabbage rolls, etc.). Grandma's food was always good, so I'm guessing everyone else's grandma's had great recipes too- those I'd love to find more of!
Back to the kitchen for me!
Michael