Cilleena I wear pumps with my jeans on most days (as you've noticed) and for me there are 5 main things I look for separate from a good fit: toe shape, heel height, material, color, style. For reference, I prefer: almond toe, 3-4" heel, leather/patent, any color, classic shape. You may want to try a few different toe shapes to find what's most flattering for your feet/works with the style you've got in mind. If you can afford two I'd suggest getting one neutral (goes with everything) and one color (colored heels add instant pizazz!).
As far as fit, make sure your toes are happy in the toe box and that they have enough room, no smashing! Leather will stretch a little, so look for something that is snug but NOT pinching; synthetics generally do NOT stretch so make sure it fits a teeny bit looser than snug. You also want to make sure the whole shoe is wide enough for your foot to feel comfortably enclosed but without gaping at the sides. The heel should be snug enough that it holds your foot in place but doesn't pinch either on the sides or at the back.
