Hey Adam
fist of all DirectX
Crossover=>Configure=>Manage Bottles=>Steam=>Applications
directx should be listed among the applications there as Microsoft DirectX Runtime
if it is not there try
Crossover=>Preferences=>InstallerAssistant and uncheck the box "Hide service packs and dependencies"
That will make some basic stuff available for install
Crossover=>Configure=>Manage Bottles=>Steam=>Applications=>Install Software and now you can choose from a list of packages
I should add that my steam bottle has directx, xml parser 3.0 and visual C++ 2005 redist installed.
The registry entries
Crossover=>Configure=>Manage Bottles=>Steam=>Control Panel=>winecfg to launch configure your bottle=>Graphics
under Direct3D you will see a VertexShaderSupport change that to hardware and check the Allow PixelShader Support box (that will create the registry entry VertexShaderMode)
Crossover=>Programs=>Run Command and choose Steam bottle and type regedit
Under HKEY_CURRENT_USER=>Software=>Wine=>Direct3D you can do edit=>new=>String Value
and name that VideoMemorySize. Select the corresponding string, right click and then Modify and type a number that corresponds to your graphic card in MB.
There are some other tweaks that you can try, like changing gdi to opengl in DirectDrawRenderer or enabling UseGLSL(just select the corresponding string vaue, right click and then Modify..,)
I would suggest to look for "Useful Registry Key" in the WineWIKI, most of them work just fine for crossover too
hope this helps
P.S. the tweak mentioned in the World in Conflict thread was meant for that game in particular, but I did not change my bottle settings, so that one is still in place. On a separate note, any change will affect all the games in that bottle, so it may turn some into non-working