Similar approach is to create a master sketch which is a sketch that defines the major dimensions of your design. You can then 'attach' bodies and planes (or LCSs) to different parts of the sketch. The approaches are similar but it allows constraining all of the distances relative to each other using the sketcher rather than hard-coding or using math expressions. It's the only workflow I've found that doesn't have me pulling my hair out with more complex designs, but it definitely has downsides too (requires excessive subshape binders, sketcher is slow, overall it feels slower than bottom-up design).

I keep making the same mistake. How do you make intermediary planes?