OCSP stapling requires Apache 2.3.3 or later. If you are running a stable Apache 2.4 branch, it is wise to take advantage of this security feature. Here is an example configuration that can be used:
SSLUseStapling on SSLStaplingResponderTimeout 5 SSLStaplingReturnResponderErrors off SSLCACertificateFile /etc/ssl/apache2/my_ca.crt SSLStaplingCache shmcb:/var/run/ocsp(128000)
Be sure to have SSLStaplingCache outside of a <VirtualHost> section or Apache will likely not start. I suggest putting the entire setting outside of a <VirtualHost> for simplicity.
Running a test on ssllabs.com will validate if this has been setup properly.