I've found the OnShape flow pretty good for this, using the Laser Joint and Auto Layout scripts he referenced - thread here: https://forum.onshape.com/discussion/14166/designing-laser-c...

One thing that wasn't mentioned is that its important to measure the plywood you're using. 18mm ply can vary from 17 to 19mm so when you're making tight finger joints its important to know the thickness of the sheets that the parts will be made from.

Once it comes to actual cutting, the tool (in my case, a water jet) will often have an auto-nester to lay out the parts, but being able to prototype the part nesting in CAD means its faster to optimise the design to fit the sheets you've got.