No I'm too impatient to learn CAD, so I used hand drawings, followed by test fitting it as I progressed.
I can do basic things in sketchup, but it takes me too long, so I usually grab a pencil and a ruler.
getting the top piece to fit, while allowing the side pieces to rest on plastic trim was the kicker. But I ended up putting single sided rubber tape underneath all the support pieces anyway,
I did Technical Drawings in High school, that helps, especially with understanding where the item will fit in the space