Some basic stuff you need to do in VMWare but will forget to when you get distracted by just getting things upgraded, migrated, licensed, etc.
All documented here: http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/virtual/servers.html
Install the VMWare tools on the applications:
Depending on what application you are running and what version, there are different techniques to do so. See here: http://docwiki.cisco.com/wiki/VMware_Tools
Disable LRO on the host:
You may experience issues with TCP performance speed. See here for modification techniques, and note it requires rebooting the host. See here: http://docwiki.cisco.com/wiki/Disable_LRO