I am in a similar situation. Been playing for around 2 years. Watching others and then practicing those CB routes has helped me tremendously. Shot selection and CB position go hand in hand.
Seeing the natural path the CB wants to take and understanding how I can and cannot deviate from it. I used to try all kinds of miracle positions and finally realized some things just cannot be done or are too difficult to attempt in a match.
I, too, am in a similar situation, tho I have a couple more years than you at it.
The thing that can become frustrating is when you start to naturally "see" some shots and leaves, why can't you apply that to every shot? As everyone has pointed out, experience is the only way for it to become natural.
It's funny, after a while, certain shots you will just "know" when you step to the table, without even thinking. I bet you already have some like that now. Think back, and those werent autopilot at some point. This becomes a fun realization as you progress, as you realize a particular shot has become almost unconscious, when a while ago you had to think it out.
That makes watching matches more fun, when you can watch others play, and start to realize that you knew what the player was going to do before he did it. Not every time, of course, but often enough that you feel that you're "getting it."
I am having a lot of fun with this stuff now, in my learning process. If I could get the execution more consistent, I would see greater overall improvement, but that's why we practice, right? I am sure you are seeing some of this already. Don't get frustrated that it doesn't happen all at once, for most of your shots, cuz it doesn't work that way. At least it didn't for me. You will really learn certain shots one at a time, at least to knowing them at that level. Experience, sadly we cant rush it....
Keep on keeping on....follow these instructors advice, as they are a great resource for us all. Have fun, and good luck.