Not getting your entire subject in the frame
Whenever you go over your photos you will hate the moments where the photo you like the most, you failed to capture your subject entirely. Unless doing it on purpose, always capture your entire subject. You can always remove parts of the photo but never add on.
Shooting during broad day light
Light is essential for photography, it can make or break photo. During the midday, everything just looks super boring in general. When starting out try to take photos during the golden hour, first hour after the sunrise or the last hour before the sunset. Of course, it depends what kind of photography you are doing, but in general warmer and softer light is better.
Not taking (enough) photos
The only way to learn is to go out, take photos and make mistakes. Go over all of the photos you made during the day and ask yourself why do you like certain photos and what would have made other ones better. And then go out making photos again. Basically, repeat this pattern, forever…
Not shooting in RAW
DSLR and mirrorless cameras support RAW image files, even some smartphones do. This allows you to alter certain setting after you have taken the photo in post-production. Shooting in RAW will make you a lot more flexible and dynamic when taking photos.
Yes, I am going to repeat this again, and again, and again. A crooked horizon is such a waste to a great photo. Not only do you lose some of your photo when you are going to correct it, it just does not look right. Pay some extra attention when you are making your shot, and of course it will not always be straight. But for that there is post-production software
Monday: foodphotography and animalphotography
Tuesday: landscapephotography and cityscapephotography
Wednesday: architecturalphotography and vehiclephotography
Thursday: macrophotography and colourfulphotography
Friday: streetphotography and travelphotography
Saturday: sportsphotography and smartphonephotography
Sunday: goldenhourphotography and longexposurephotography