The following settings are recommended up to CATIA V4.2.5 (Dassault) and NX 11

CATIA V4 (Dassault) - System

• No elements should be placed in NOSHOW/NOPICK.
• Model should be cleaned of all unused information, because the translator exports the complete content of CATIA-parts.->Delete:
• Unused  DETAILS  (in all workspaces)
• Unused elements from  NOSHOW</> (in all workspaces)
• Drawings
• Update SOLID-M into SOLID-E with CATSOE utility.
• Perform SOLIDE/UPDATE, also if message UPDATE ALREADY DONE appears. (Regeneration removes inconsistencies.)
• Generate Volumes from SOLID-E and delete SOLID-E in all workspaces. (Geometry is still exported as a solid in STEP.)
• Scaled and mirrored dittos (EXPLODE function) should not be used. 
• Before export elements of special CATIA modules (e.g. PIPING, BUILDING DESIGN) need to be converted to STEP compliant elements.
• Use CATCLN.
• Assembly structures in SETs should be transferred to DETAILS.
• All FILTERs should be deactivated (LAYER -> FILTER -> ALL).
• Solids/Volumes consisting of separate Bodies should be avoided.
• Objects used for Boolean operations should show good penetration.

CATIA V4 (Dassault) - STEP Preprocessor

• Option "Use Short Names" should be deselected (unless appropriate libraries are available). 
• Recommended settings in Declaration File:
• CATST1.STEP.USE_SHORT_ALIAS=FALSE
• CATST1.STEP.EXPORT_NO_SHOW=FALSE
• CATST1.STEP.EXPORT_UNUSED_DETAILS=FALSE

STEP File

• In the filename syntax special characters (especially / * % ) or umlauts must be avoided.
• NX - STEP Postprocessor
• Start the external STEP postprocessor with Translator -> STEP AP214 and select Import.
• Select  Edit -> Settings  and define the options:
• (or interactive from NX 8.5) To export a STEP File choose File -> Import ->STEP203 or STEP214.  
• Object Types: One or more of the options Solid, Product Data, Surface and Wireframe (depending on model).
• With the option Geometry: Sew surfaces it can be defined whether the translator sew the surfaces as they are imported or not. The default is not to sew surfaces.  
• Recommended is to use the default settings in menu Translation Control (Tolerant Modeling).
• A *.log and a *.def file will be created in the same directory as the imported models.
• Validation properties are supported.

NX - System

• Shaded view is helpful for a first impression of model quality. 
• By choosing the menu option:  Information -> Object -> Type -> Solid Body -> Select all correctly transferred solids are identified with red color. (Same way with other model types). (up to NX2)
• By choosing the menu option Information -> Object -> Objects -> Select all after choosing the filter for Solid Body in Information -> Object -> Filters -> Type Filter correctly transferred solids are identified with red color. (Same way with other model types).