I recommend starting this exercise with a travel magazine packed with lots of interesting photos. Select an image that appeals to you. Now, write a short scene from the viewpoint of a character who has just arrived at this location and is seeing it for the first time. Describe the setting through the character's eyes, paying particular attention to the mood that this image evokes in you. Evoke this mood in your readers through the reactions of the character - look for sensory images!Now, write a second scene, with the same or a different character - and evoke just the OPPOSITE mood. If your castle seemed tranquil and romantic, set a scene in which the mood is menacing or sorrowful. If the image of that tropical beach made you feel relaxed and happy, create a scene in which, instead, it is causing your character to feel angry or anxious. Again, look for sensory details and impressions that will convince your reader and evoke that same mood through your words - regardless of what mood the picture alone might have evoked!