My general advice is to take TONS of photos -- and when you aren't taking photos, think about how you might take pictures of whatever situation you're in and how they might look.
Photography is all about geometry, texture, weight, and subject. Eventually, you'll think about this stuff all the time in everyday life.
You could take a course (feedback is always a help) but you really just need be taking pictures or thinking about taking pictures all the time.
Also, some specific advice: actually learn the mechanics of your camera. I see lots of amateur photographers who have good pictures, but whose stuff would otherwise be 1000x better if they just understood how changing the aperture/shutter speed effected their photo. Along with this, you'll need a tripod for low speeds, and a good tripod is worth it -- as a general rule it should be heavier than the camera (I have some horror stories of $4000 cameras on flimsy tripods, lol).