Want the option to tie all “future” extrusions in a part to the thickness of your part ?
After you do what ever you need to do to make the first feature of your thin part (extrude & shell, revolve & shell, or just extrude, etc.)
LINK the value of the dimension that would be your “thickness” to a variable name called “Thickness”. (just double click the dimension, click on the Pull Down arrow next to dimension value, and choose Link Value, then type “Thickness”)
This will “trick” SolidWorks to turn on the “link to thickness” option in all your FUTURE Extrude, Cut, etc. commands just like when you are in a sheetmetal part !!
Then you just keep on modeling and turn ON this option as needed !!
Pretty COOL !!