Every once in a while I'll go back and look at some of my earlier work as a photographer. It may not be helpful critiquing your most current crop of images, but looking at past images we can see what we were doing wrong and what we do now that makes are images better. Here's my top mistakes I made as a beginning photographer.
1) Including too much in my image - As a beginning landscape photographer I wanted the widest angle possible and I included as much of the landscape as I could. Many of us have heard the saying, "zoom in to get close, now get closer". Some people take this to the extreme but the point is simple. Don't try to include everything you see. Simplify your images so they include just a couple elements. Most often less is more. Too many elements are distracting and considered cluttered. It invokes feelings of stress and anxiety instead of calm and serenity that well composed landscape images are known.
2) Over Processing - I would add too much saturation, too much contrast, too much clarity and sharpness. I over processed without direction or purpose. Almost all of my workflow was flawed and inconsistent. My early work is right about the time HDR was becoming really popular. I tried HDR and I liked it. Some of my early HDR stuff is horrendous. It should never be seen or even talked about again. Don't get me wrong HDR has it's place and I use forms of it even today, but the reason I was using bad processing techniques was to make up for bad lighting. Bad lighting can't be fixed by any software or photo editing workflow. That leads me to my number 3.
3) Shooting in Bad Light - I would photograph when I thought it was convenient, not when the light was at it's best. I knew I was supposed to shoot at Magic Hour, but I didn't think it was that important. Besides I was using HDR so my photographs were going to look great! I know better now, but just to reiterate, shoot just before/after sunrise and sunset. Your images will show tremendous improvement just by following this one tip. You won't need over process your images and in some case you may only need a minor tweak.
4) Not Caring About Your Subject - I did some product photography back in the day. They weren't bad images per say and I still sell them as stock images, but I didn't enjoy my subjects. I like learning new things so product photography had me interested in working with flash and reflections. After a while I was bored and in the end I didn't like doing it. Passion and interest was no longer present and therefore I wasn't making images that met my personal standards. Having passion for your subjects is a key part of making quality images. This could mean landscape or wildlife, even portraits and weddings. If you don't love it, it will show.
So looking back at my images I can see what I was doing wrong. At the time I thought it was great. People were telling me the pictures were fabulous, but I really had no idea how far I would come. I sure do have a lot more to learn and my most current work will hopefully improve over time. The bottom line is you have to practice and increase your chances of great images by being in the right place at the right time. Learn what you have to do to become better, and practice it. Your images will eventually thank you for it!