Here's just a few tips I've come to realize from a lot of photography and picture taking. Hopefully these tips will help you with your photography! :))
General tip: NEVER take pictures between 11am and 2pm. The sun is high in the sky and doesn't give your pictures any depth from the light. I like to take pictures early in the morning or in the evening around sunset. The colors of the morning/evening skies give your pictures depth and interest because of the shadows it casts.
Another general tip: Find something interesting to take a picture of and focus on it, but make sure it has an interesting background to give it little bit more than just the subject of the photo.
Flower pictures/close up: Find the flower setting on your camera, this helps a lot when you're taking close up pictures of flowers, bugs, etc. Use the focus liberally. Your focus will blur what you don't want to see and make your focal point very clear.
Scenery: Find a place with a lot of color and something interesting to look at. If your picture doesn't have a lot of color or something interesting going on it'll look blah and not very appealing.
One final tip: TAKE LOTS OF PICTURES!!!! You can always go back through later and delete, but the more pictures you take the better chance you have for taking a picture you love!