SharePoint 2010 to 2013 Migration steps

• Run data statistic scripts to SP2010 Support site collection before mounting content database.

Test-SPContentDatabase -name <<contentdatabasename>> -webapplication http://<<WebApp_URL_2010>>/ 

• Create a Web Application in SharePoint 2013
• Check whether account using for migration have following accesses

DB Owner Permissions on following databases.
•  SharePoint_Config
•  SharePoint_Admin_ [GUID]
•  Content Database (newly mounted content database)

"SharePoint_Shell_Access" permission on “SharePoint_Configuration” database. (For running PowerShell command.)

• Remove attached content database of newly created 2013 web application and mount production 2010 Content DB in SP2013 webapplication

Mount-SPContentDatabase "WSS_Content" -DatabaseServer "<<DatabaseServer>>" -WebApplication http://<<WebApp_URL_2013>>/ 

• Converts the authentication mode of a web application from Classic to Claim

Convert-spwebapplication –identity http://<<WebApp_URL_2013>> -to Claims –retainpermissions -force

• If performed any customization in previous version(code). Then migrate this customization in SharePoint 2013. Note: Code runs on .net framework 4.5 & components deployed under 15 hive folder instead of 14 hive.
• Deploy migrated code & do all configuration changes required for e.g changes done in web.config file or central admin level configurations.
• Open migrated sitecollection & it will require visual upgrade

Now basic migrations steps are performed.