How do you determine "ride height" to make suspension mods??

UPDATE::: Finally got my mock up mdf/plywood wheels and tires done.

Here is what I mocked up to help determine my ride height:

wheels - 18" painted silver (cause that's how my brain works)

Rear tires - 335/30ZR18 -- 25.9" Overall diameter and 13.5 overall section width on a 12" wheel -- painted black (cause that's how my brain works)

Front tires - 235/35ZR18 -- 24.5 Overall diameter and 9.5" on an 8.5 rim ---not set on this tire and wheel width due to fitting issues, but needed to pick something and a 24.5 in tire seems to be the recommended size. -- painted black (cause that's how my brain works)

I even skinned one of the rears in black just to get a feel for the width when I mock up under the tire. Looks narrower than I want, but a 26" tire seems to be a good starting point for determining my ride height. Anyone running a taller tire on an 18" wheel with a mini tub?

Hoping to get the car off the rotisserie soon to try them up underneath to set the ride height.