We use a very similar, if not identical, folder layout to what Ty described.
When designing in the Multi-Part-PartStudios we try to have the first sketch be the “master” driving sketch for the major components of the studio. The idea is to make it easy to modify a set of parts without having to find the right feature in the tree.
For example our elevator geometry is mostly all in the first sketch:
We learned late in the sason how to precisely position parts made with the Custom Length Extrusion FeatureScript. The trick being make a sketch on the plane where one end of the part needs to start and place a point in the sketch at the center of the extrusion.
If the extrusion needs to fit between two parts in a PartStudio you can make the extrusion undersized then use the Move Face tool to move “up to entity”.
We are also heavy users of the Lighten Feature Script to make the awesome cutout patterns with a CNC.
We found that many teams are making great use of the MKCad parts library however due to the many copies it can be challenging to link to the version that is kept up to date. We found that creating a label and adding just the original MKCad files to the label makes it much easier to find the desired part in the insert dialog:
We also learned the hard way that linking in parts and assemblies that change often from other documents was quite a nightmare. We use a single Onshape document for the whole robot and only parts that do not change (ex: Gearboxes, Motors…) are linked in from another document. The challenge of constantly updating parts from other documents wasn’t worth the potential benefits.
Here is our full robot: