Things that you should always keep in mind when you want to take pictures:
Never forget to compose your image, if you just let the chance make things you may end up with compositions that will make the picture uncomfortable to look at. If it's a portrait or a close up of object ( or food...) make sure to have the subject in the center . Exceptions can be made if the background have something to show, or if you want a close up to a part of the face to add some mystery or simply cause it artistically will make something interesting.
Speaking of Background... never forget it! Some details can make the whole photo a mess. A color too bright may take interest when the subject will lose it, the background can also simply be ugly or have strong lines of perspectives that could unbalanced your picture. So... never forget it!
As example here: someone passed just as I was shooting so I have a elbow in the way and it's kinda annoying for the eyes!
Pay attention to the color harmony,some colors goes well together by fading in each other or by making each other more intense. If you can avoid it NEVER take Black and white pictures. You can turn any color pics into B-W on any pictures program. Black and white may help to get pics that look well balanced as there is no need to care for the color, but You may lose a very nice harmony of color by pure laziness ( don't deny- it!).
When you want to take a good picture, please forget your need to look cool... move around your subject try different angles, lights... If you have to climb on the table DO IT ( wen you're at home :p don't climb on other peeps tables without their permission...)
Last but not least ( and maybe even the more important)... The Light! The best light is the light
from outside not the direct sun tough, it can "burn" the picture ( make de white zone Absolute white, by so: Flat.) If you're taking picture of food or object taking them out , in the garden maybe a good idea. that's for general pics. When it come to low light pics or night shoot it's another story... i'll make another article about Light in photography only with the basics of how work a camera so you'll be able to understand better!
I hope this as been useful and will make you feel the need of taking lots of great pictures!
Enjoys!