When I go on my photo walks, I have a few guidelines that I mostly adhere to - they seem to help the creative result.
1. Enjoy being outdoors and aim to get into a flow of some sort. Attempt to let troublesome thoughts take a back seat and pay attention to what is around me.
2. Try to get the best picture possible of whatever the subject is. If taking a picture of a stationary object, take the time to get the setup right. Otherwise, get the camera ready ahead of time to take pictures of moving critters.
3. Hope for seeing and photographing something "new", i.e. that I haven't taken a picture of before. (Yesterday, I got a shot of a Tiger Swallowtail - they are common and I've seen them before, but never photographed)
4. Sometimes it's ok to just watch and not take a picture.
5. Take a picture early in the walk even if it's a throwaway. It breaks the ice. Pixels are cheap.6. Sometimes nothing works. It will next time.