Harlan Brumm at Revit Clinic posted a number of really useful tips when using the new massing tools in Revit Architecture 2010. Below are couple of extra tips which expand on what he suggested.
One the nice features within the 2010 concept massing tools, is the ability for a void object to automatically cut solid objects. If you create a solid form and then create a void form, they just cut. However, what happens if you have two solid forms which are overlapping and then you add a void form? By default, if the void form intersects both solid forms, it will cut both solids.
Now this is fine, but what happens if you then decide that you only want the void to cut one of the two solids? To do this you will first need to select the intersecting void. However, the problem is actually selecting the void. The best way to select the void is to move your point over the void and tab select, cycling through the selection until you pick up the void.
Once you've got hold of the void you can then choose uncut geometry from the modify tab, then select the solid you don't want to cut.
Can't add a profile or split a face?
If you join to solid objects together, although you can go into x-ray tool and see how each individual form is made up, you will not be able add a profile to either form when in x-ray mode. You need to first unjoin the two solid forms if you want to add a profile.
The same situation occurs if you have two solids join and you want to split face of one of the solids. Again, you need to unjoin, before using the split face tool.
When working with massing we can divide a surface and apply a surface pattern to a divided surface. If you divide a number of surfaces and a apply a surface pattern to one of the divided surfaces, we can use the "Match Type" tool to match the surface pattern to multiply divided surfaces.