Practical tips on making better photos on iPhone (or any phone camera):
All photos shot on iPhone Xs
1. Look up

To make better photos, don’t just look eye level. Look up! Play with the colors, and also try to align elements on the edges of your frame.
2. Honor thy selfie

Put yourself into the picture. Take different variations of the photo:

Also when shooting phone shadow selfies, separate your phone from your head, to give yourself more of a clear and crisp outline/silhouette. Go for “edge detection” (outlined in red):
3. Simple colors
Simpler photos are better photos.
Note the above picture — simple blue on top, green dollar, and red, and yellow:
4. Social commentary

To shoot better photos also means to photograph more things which have social importance or impact.
For example something I abhor in poor communities: predatory payday advance services.
5. Simple shapes and forms

Practice your composition with simple diagonals, triangles, and other shapes and forms. Shoot shadows, reflections, or anything which appeals to you.

7. Shoot during sunset

If you want to capture epic light and shadows, shoot during sunrise or sunset (golden hour). No amount of filters or processing can make the golden colors come out — look for the light!
8. Use VSCO

For color, I love the VSCO A6 preset.
Experiment with VSCO presets, to find presets and aesthetics you like.
My tip:
Process your pictures until they look good in your eyes, then stop.
9. Use the default iPhone camera app
There are lots of third party cameras out there, but keep it simple. The default camera app is the most simple, fluid, and intuitive.
10. Turn off smart HDR, turn on Grid
Smart HDR doesn’t make your photos look better. Turn it off, in the “Settings”:

11. Lower the exposure (brightness)
If you’re shooting in a bright situation, lower the exposure by tapping the screen once, then dragging the little sun icon downwards:
By lowering the exposure, you will make more dramatic photos, with better contrast
12. Simplify your composition
The best composition is the simplest one.
When you’re framing your scenes, check the corners — to make sure the corners and background of your photo is clean.
Conclusion

The phone is the best camera. It is always with you, you can instantly select and process your photos, and share them online.
At this point, almost all new smartphone cameras are good. This includes iPhone SE, iPhone Xr, or any iPhone after the 6s.

Of course there are downsides to shooting with a phone camera. The low light (indoor) abilities aren’t great. If you want a low light phone camera, I highly recommend the Google Pixel 3 instead.
But anyways, shoot anything you’re interested in, have fun, and remind yourself — the phone is a legitimate camera.
Just shoot it.
ERIC