Reply to Thatman_Blaze:
First of all, go to practice. 1st player Ivy, 2nd player Astaroth (i'll explain later why Astaroth, it really doesn't matter though)
(I'll cover the CS part, but the same applies to SS, only reversed)
(Also, I should mention that I'm using a PS3 pad, which is very CS/SS friendly)
Shift to Sword State (B+K), then start doing the CS motion input VERY slowly. Of course doing it very slowly, nothing will happen. But it doesn't matter. Just do VERY slowly the following command:
3214123691A+G
Just remember to press simultaneously the last input with A+G. The last input as you can see is the "1" input. So "1" must inputed TOGETHER with A+G. Like: 1+A+G
Also, do not raise your thumb from the d-pad during inputing the whole command. Remember (while doing it slowly as I said for a start) to maintain a smooth movement. Doing it slowly at first, will make you familiar with the movement.
Now, when you think that you are familiar enough, try to do it A BIT faster (just a bit). And so on, each time that inputing speed does not affect the smoothness of movement, increase your inputing speed. Remember: Take your time. Eventually will do a CS.
Of course doing it while standing, Ivy moves like crazy (it's very funny watching her). So now you are going to try it, while buffering the input during a move. In Sword State, FC3B is a move that allows a rather big buffering window. Just do SW FC3B and during the animation of the move, buffer CS.
Next try a quicker move. Let's say SW 2A. As you can see, this needs quicker buffering than the previous move. IMPORTANT: You should know that MOST moves do NOT allow buffering CS in their starting frames, so for MOST moves you should start your CS buffering "sort of" at their ending frames (well, this needs a more in-depth explanation, but for now i'll leave it as it is).
Finally, try CS during blockstun. Record Astaroth's 22_88B and while blocking it, buffer CS (this Asta's move has nice blockstun). Remember, even during blockstun, do not start your CS buffering exactly at enemy move's impact, just sliiiiiiiightly later.
(I should repeat once again, that the most important part of this practice, is the part when you get used to the command while doing it very slowly, while standing. Take your time, with this and each time, try to increase your speed until you get a beautiful CS or iCS)