I've got a lot of experience & comfort in meshing the fluid regions of SW Flow CFD, but am starting to do more conduction/radiation analysis, which involves more emphasis on the solid mesh.

My general approach to fluid meshing is to ensure that all my fluid channels have at least 3-5 cells across the width as a starting point.

Are there any "go-to" rules/tips/tricks when approaching a solid mesh? Should I be striving for a minimum number of cells across a solid width? That seems like it would really drive up the total cell count, especially for something like a thin solid...