Keep an eye on the weather outside. Weather conditions can create many opportunities to improve or destroy a great picture. You can still get some great outdoor shots on a cloudy day. Compose your photos so that the gray sky is not actually in the frame. Don't let it stop you from taking great pictures.
Make sure the background you choose complements the subject of the photo. If you take a photo of a model against a busy background, the viewer's attention is going to be drawn to the background rather than the clothes. As a general rule, simple backgrounds with colors that contrast with those of the subject are ideal.
Use speed when capturing your pictures. If you take too long, the subject could move, the sun could move behind a cloud or it could start raining. Anything could happen, so don't delay. A camera which allows you to make quick photos will give you the best results.