Nice free Office 365 migration tool by @joslieben
O365Migrator
O365Migrator
http://www.spjeff.com/2016/12/15/insane-move-sharegate-turbo/
http://blog.ciaops.com/2016/07/a-handy-sharepoint-migration-tool.html
http://sharepoint-community.net/profiles/blogs/why-pre-migration-analysis-is-crucial-while-migrating-data-from