Here's a fun exercise that I like to do. You can either absorb things uninterrupted and write them down later, or, do what I do, record the experiences as they happen.

Think of a favorite place you like to go. Close your eyes and try to picture the setting. Are you there? Are you outside, feel the wind, or absence thereof. Are you indoors? What do you see? Are there any smells associated with this place? Can you remember what it's like to touch the things surrounding you? Do you remember tasting anything on the air, the water, or did you eat something while there? What was it? What was the texture? Did you like it, or not? How did you feel while in this place? Did something happen there, or not? Was something absent? Why were you there? Will you go again? If not, why? You get the idea. There are so many more questions you can ask. Now, make sure you record everything in minute detail if you haven't already.

With fantasy, you can take these observations to a different level. Let your imagination run wild. The impossible can happen. Flip things around. Think of different demensions. Can things merge together to create something else? Have fun with it.