Here are some quick tips for taking better pictures under most normal situations. 

1. Pay attention! Photography is important!
2. Avoid camera shake at all costs - shoot at shutter speeds at least above 1/60 or reciprocal of focal length for longer lenses.
3. Avoid out-of-focus images at all costs - pay attention to focus points and your subject. 
4. Use Auto-ISO with a minimum shutter speed of 1/60
5. In decent light, set your camera to Aperture priority (Av) and set Aperture to 1-stop narrower than the lowest f-stop supported by your lens.
6. In late evenings or under low-light, set your camera to Shutter priority (Tv) and set shutter speed to 1/60 or faster
7. Composition:
   1. Keep it straight
   2. Don't cut people's limbs
   3. Don't make people flowerpots
   4. Take multiple shots when shooting groups
   5. Experiment with off-center focus points
8. Use prime lenses 
9. Use cloudy white balance outdoors and tungsten indoors
10. Shoot earlier in the day or later in the day, avoid noon
11. Use an external flash when shooting indoors
12. Take photos in burst mode specially in low-light and keep the one most in focus
13. Go with a simple exposure of "Av f/5.6 ISO Auto" for life's important moments!
14. Use an external flash, set it on automatic and point toward the ceiling for indoor shots
15. Use a tripod - make sure to turn off stabilization on the lens
16. Use manual focus point selection to precisely select where you want to focus
17. Post-process, post and participate in photo sharing services and social media
18. Participate in a photo project
19. Print photos, calendars and photo books
20. Backup your photos!