A summary from TechNet (available at https://technet.microsoft.com/en-us/library/hh825108.aspx ) and experiences from the field are outlined as follows:
Install applications before running the LoadState tool: This helps ensure that migrated settings are preserved. For Microsoft Office, this is required for migration to work correctly.
Do not use MigUser.xml and MigDocs.xml together: If you use both
.xmlfiles, some migrated files may be duplicated if conflicting instructions are given about target locations. You can use the
/genmigxmlcommand-line option to determine which files will be included in your migration, and to determine if any modifications are necessary.
Use MigDocs.xml for a better migration experience: If your dataset is unknown or if many files are stored outside of the standard user-profile folders, the
MigDocs.xmlfile is a better choice than the
MigUser.xmlfile, because the
MigDocs.xmlfile will gather a broader scope of data. The