As you know Parker spoke always of building block letters. Now when he spoke of this he did it in different contexts. The most fundamental context he used was that the block letters of the Kenpo basics were the old more extended karate basics. The karate basic prior to being tailored for American Kenpo. So in my school of thought it is extremely important that a person be rooted in the root basic in order to appreciate and perform the kenpo version. One must understand a corner before one can round it. One must know a line before arc it. One must know a circle before one can tighten it to an ellipse.
1. Square Horse
2. Front Stance
3. Inward, Outward, Upward, Downward Blocks
4. Reverse Punch
5. Front, Rear, wheel, side kicks
* Step and punch, counter punch, Neutral stance, back stance and fundamental drilling of all the above
These things should be ingrained prior to any "Kenpo" in my view. Also with a caution that some karate styles lead better to American Kenpo than others