Foundation is correct. Mirror training is a very good way to check your technique and reduce telegraphing.
Sparring practice will also eventually get you there, but mirrors don't hit back!
Work on making your movements as "tight" as possible ie; no wasted motion. This will improve your speed, making it harder for the opponent to defend.
Here is a copy of a post I did a while back that you may find relevant as well:Obscure zones
One of the more subtle and misunderstood principles of American kenpo. Very effective when properly utilized.
Obscure zones are areas where your opponent can not see or has extreme difficulty seeing where attacks are coming from.
1. Attacking from behind the opponent is the simplest way to "obscure" your techniques. Nobody has eyes in the back of their head, so it makes it much easier to sneak a technique in.
2. Mechanical disruption of opponent's vision. This can be done many ways :
The dreaded eye-poke/rake/claw, etc. I don't particularly recommend that unless you truly feel your life is in danger.
Covering the opponent's eye's. This can be done with your hand, clothing, paper napkin, opponent's own hand/clothing, etc.
3. Distracting the opponent. A finger snap ( or tap on the shoulder, light slap to the face, etc.) to the left side, while throwing a hard KO technique to the right side.
4. Starting techniques past the opponent's peripheral vision. This involves throwing strikes that travel up or down and behind the opponent's upper arm or shoulder, limiting the amount of reaction time they will have.
5. "Tracking" strikes across the opponent's body. Related to #4, use the curves of the opponent's body to hide strikes until it is too late to stop them. Example:
The opponent has a hand out towards you, you shoot a punch to the ribs that tracks directly under the opponent's outstretched arm. From the opponent's point of view, his/her own arm will hide your shot until it is most of the way there.
Many boxers throw hook punches in a similar way by hooking the punch very tightly around the opponent's shoulder, outside of peripheral vision.
Excellent concept that can be applied to any martial art, very effectively. Enjoy.