Although I have only been doing photography for six months in a serious business like way, I still have advice for newer photographers. Three things that I wish I knew from the very beginning.
1. use auto focus
I remember I seen a Youtube video about how you shouldn't shoot in Auto focus that you can't control the focus and that you should only shoot in manual focus. Boy was that guy wrong. Using manual focus I struggled with the focus being soft. I tried everything and I was so frustrated. Through talking with fellow professional photographers I find most (if not all) shoot in Auto focus. I switched and it made a lot of a difference.
2. expose for what you want to see
This is particularly useful if your subject(s) are wearing bright colors or white. white can be easily be over exposed which will have them glowing in a bad way. by exposing for what you want to see you can ensure you have a good picture you can always fix some things that might not be properly exposed in post editing. Below you can see picture on Left the blanket is glowing as I forgot to expose for it vs. the Right the dress is properly exposed
3. Shoot in raw
I was told this a lot, but I always ignored it as I love my jpegs (for whatever reason). Raws are your friend though. There were photos in jpeg that I couldn't save due to being over or under exposed, but once I switched to raw, those same issues I could fix and save more photos!