crosswind techniques

Last few trips have been longish hauls with onshore winds creating small but messy wind chop. Made me wonder if I could improve my technique in these conditions as I found it way slower and harder than it would have in my touring kayak. Felt like I was missing something as it came down to stability rather than getting any real power down and technique was just going out the window. This was not even big conditions.

Feel like there must be some tricks I am missing, other than just zig zigging to angle into the wind

I get these sort of conditions pretty regularly (if are indeed taking about similar conditions). It just shakes you around without invoking secondary stability. Happens a lot on smaller bodies of water.
Here is my humble findings so far.

Hip pads and snug foot straps help a lot.

Posture. Sitting up and leaning forward channeling your weight down the bucket and a little bit on the adjacent area of the hump. It's a bit counterintuitive but it does help.

Feet together with heels apart creates a stronger position and generally thinking "strong at the plate" if you know what I mean.

Wider stroke with some lat engagement purposely channeling power sideways, but not a huge amount.

Closing eyes and asking yourself how much of imbalance there actually is. I sit on a swiss ball almost every night and the question I would ask myself is "how unstable it is in swiss ball terms". Usually much less than on the actual ball.

Light preemptive bracing if required, keeping your mind in check and scaling down on the effort to keep good form. Last thing I need is to start wrestling the elements. Easy and deliberate is faster and more comfortable.

If things go haywire, come to complete stop, leg out (I usually sit completely sideways) and ask yourself how bad it actually is. Usually feels not as bad as it did just a  minute ago. 

Keeping legs relaxed in-between pushing is a big deal. Our instinct is to balance at the point of contact with the supporting surface which is usually the least effective way of balancing. We have so much more leverage above waist line.

Keeping chin down. Kenny Rice said that our balance comes largely from our head. I think there is a lot of truth to that.

Something like that.

Correct location is shallow bay beaches where the there is no swell to speak of just localised wind

Thanks that aligns with the ideas I was playing with, especially the psychological aspect about just letting the boat wriggle about a bit as individual waves are not big enough to counter, nor are they big enough to throw you. Unless you start getting jumpy and trying to over correct. It is easy to "let it roll with the flow" on a sea kayak as they are designed for edging whereas as a ski is not normally used that way. So I guess its about gaining confidence on letting it go. Practising with eyes closed I think is a good trick as it really has to be instinctive response rather than visual response, as there are no individual waves to watch

I tend to lean further forward, take shorter strokes with maybe higher cadence.  Relying on standard paddle bracing to one side is less secure due to the tipping movement rapidly fluctuation from one side then to the other.

I find it much more taxing once you are starting to tire, and I just want to be off the water then

Other than the mental aspect, how is your boat fit? I found that hip pads help a lot. I made 2 cell-phone sized foam pieces wrapped in tape and placed at the widest part of the bucket closer to the upper edge. Not tight, just enough to touch me. Once the boat starts rolling it comes to contact with hips which basically inhibits most of the roll.
And like I mentioned in the other thread, snug strap is useful to reign the boat in and remain centered. You can pull with the top of a foot a little while still pushing at the heel. These two things reduce the roll a lot almost to the point it's not even happening that much anymore.
Yeah side bracing is just a means to calm down. 

Depends on where you are at with your technique. There is a strong tendency to "juggle balance" with newer paddlers, something I used to do without really realizing it. The problem is that this is a very reactive way of paddling. Because the ski is predicated on responsiveness, it's incumbent on the paddler to become totally fluent in what they tell the ski to do. So the goal then becomes to focus on building your connection skills in order to tell the ski what to do. Connection based balance is less about reacting to what the water is doing and instead focuses on being powerfullly connected to your ski, and the water. 

For example, the first thing to go when a paddler feels rattled by conditions is the foot pressure on the footplate, which also takes pressure off of your butt... and then your paddle is no longer helping you very much and is actually a huge liability. If you loose foot pressure, you loose your connection to the ski. If you focus on good footwork, you'll find you have equal parts pressure on the foot board (from the heel of course), your butt and your hand - and that's a tripod that is very very stable. 

I am big believer that the best brace is a great catch. If you have your footwork down, then your catch is where your mobility and power comes from - including your balance. It's counter intuitive when the water is messy, but having a great catch and upping your wattage will make all the difference in the world to power through messy water without bracing. If the paddler is prone to juggling, chances are they are rushing the catch to make balance adjustments, which is workable until you drop the ball or misjudge the water and then have to do a low brace... once that happens you've lost momentum, focus and have to get synced up with the water again. Not good. 

A handy drill that I teach to help with this is to paddle in slow motion in figure 8's to focus on the connection skills and break the juggling habit. Start with flat water, then move to light rebound, then big rebound and finally start doing these drills in big downwind conditions. Once you get solid in slow motion, you'll find yourself totally connected to the ski no matter what the water is doing, and able to paddle fluidly with power, grace and speed (the whole point of surfski...). 

Where I paddle is always cross wind. I find it easier to watch the wave and anticipate. Passing the front and back side of the wave tends to pull the boat side way in different directions. That is pretty consistent so you can anticipate. Wave hitting the front or the back of the boat causes it to yaw and steer the boat in a different direction. Watch that so you don't loose your balance. When you are high centered on a wave and you are paddling on one side, there is a tendency for the boat to turn. You can use that to your advantage if you watch the wave.
The exception is when waves are crashing on the jetty, you are next to it, and the condition is just like boiling water. Good thing is in that case, the boat average out to being upright even if you don't do much. 

Cryder nailed it.  Gotta keep attacking rather than getting caught back on the defensive.  Key to learning this is paddling where you are not afraid of capsize because it takes big stones to commit to your technique when the water is knocking you around.  Much respect to the folks who can learn this well in cold water....

You can't really watch individual waves in small cross chop when they shake you at 1 sec interval or less. It comes down to how solid you are with your boat connection and technique. I have periods when things go right and the boat just barrels forward and does not react to the chop. Other times, say I don't have my hip pads it just shakes around which just takes the power right out of the whole thing.  A good general balance helps not to swim but here is no flow and power.