I use foam or wood wedges, depending on what I have around, on each side of the skeg.

I've also added verticals to the sawhorses and put nylon webbing from one to the other to act as a sling.

The sling is easier to adjust but the wedges stay adjusted better.

Good luck,

Laszlo

i use wedges (as described by lazlo above)  especially if i need the boat to hold still as i work on the inside.

secure your wedges to your saw horse securely.  friction while nice, may not hold if you bump the boat.

you may also need to adjust the height of your sawhorses to keep everything at at a comfortable working level.  my sawhorses are made with 2X4s held together with deck screws and i have long legs and short legs that i swap for the stage of work i am at to keep the boat at a comfortable working level for the step i am working on.   adjustments can be made with a sling as well.  just keep in mind that changing the height to adjust to what is comfortable is a nice feature of any system.

h

   Could you please post pictures of these contraptions?

Thank you! 

there are a lot of different brands.  i use something similar to this one....but that has a little heavier build. 

https://www.amazon.com/Highwild-2x4-Target-Stand-Brackets/dp/B07HT15MKH/ref=sr_1_11?dchild=1&keywords=sawhorse+brackets&qid=1612987032&sr=8-11

anyway, you can see that it is pretty easy to have an extra set of legs and cross bars.

h   

  I use foam pipewrap on the sawhorse to protect the boat and sometimes put clamps under the pipewrap to steady it or prop it up. 

Yes, foam and clamps are very convenient for amaller boats, such as kayaks.

Easy to adjust, cheap and readily available, For heavier boats, like dinghies and skiffs, they're not as stable as wedges.

Laszlo

The sawhorse under the bow will keep an Eastport Pram pretty steady, even with the boat just sat on the skeg at the stern