Drupal migration process

Turn off clean-urls
Set to maintenance mode
Enable default themes, set to garland (else also causes blank screens like memory issue)
Download app code and DB
Install just drupal on new server and test
Disable clean urls, uninstall drupal, truncate DB
Restore app DB
Clear caches
Restore app code
Enable www redirection in .htaccess if required
Modify app settings file, set permissions
Set permissions on folders default and files
Enable clean urls
Check update.php, increase memory in PHP.ini to 32/64 if insufficient
Remove from maintenance mode