Photos taken with Nokia N8 Belle OS.
1. Mobile phones cameras will always have restrictions. Therefore, learn to "fight back" with these restrictions in mind. Therefore, learn composition. A well composed image will offset a crappy cam phone quality, but a good settings on a DSLR will not necessarily show good composition if you don't know anything about it.
2. If you can't remember all the rules, then understand principles.
E.g., You have that rule-of-thirds rule to isolate foreground relative to the background. Doesn't matter if they completely align with the grid, but still have that sense of depth in mind.
3. One major advantage of mobile phone is that you can always "toy around" with the angles. You're not carrying a heavy device, you might as well be really really playful with your angle choices.
4. If what you have is a mobile phone camera with a wide-angled lens, use it to your advantage. Be daring enough to make your camera cover a wide area worth seeing.
5. Mobile phone cameras suck in low light. Be aware of all the light sources present. All light sources. They spell the difference between a crappy shot and something that may look really really good.
6. Adjust exposure level if night shot jpeg noise annoys you.
7. Use black and white mode to emphasize contrast.
8. Disregard flash if ambient lighting is good.
9. If your mobile camera has a built in filter, you might as well be gutsy enough to take a shot at the sun.
10. If your eyes tell you that what you see is beautiful, it probably is. Take a shot. You can concentrate on the trivial details later (e.g., composition). Your mobile phone has lots of memory in it, you can ignore memory space.
11. Night shots significantly slows down shutter speed, and thus most likely to have motion blur. Keep your cam as steady as possible if you don't have a tripod.
12. Subjects that move need optimized shutter speed (even if this may sacrifice light absorption).
13. You can crop if there are really unwanted areas on your image. If it's a wide-angled lens, you're likely to have those. Though personally, I don't do lots of cropping.
14. Focus point need not be just one entity.
15. In certain cases, mobile phone cams aren't far behind from DSLRs.
Canon EOS 650D