MaxKeepAliveRequestsIt's actually the maximum number of requests to serve on a TCP connection. If you set it up to 100, clients with keepalive support will be forced to reconnect after downloading 100 items. Default in Apache is 100, you can increase it if you have enough memory on the system. If you are serving a page which contain high number of images then keeping is high is better because then it utilize the alive connections to serve the image requests.
KeepAliveTimeoutKeepAliveTimeout determines how long to wait for the next request. Set this to a low value, perhaps between two to five seconds. If it is set too high, child processed are tied up waiting for the client when they could be used for serving new clients.
MaxRequestsPerChildThe MaxRequestsPerChild directive sets the limit on the number of requests that an individual child server process will handle. After MaxRequestsPerChild requests, the child process will die. It's set to 0 by default, the child process will never expire. It is appropriate to set this to a value of few thousands. This can help prevent memory leakage, since the process dies after serving a certain number of requests. Don't set this too low, since creating new processes does have overhead.
Proper user of MPM (Multi-Processing Module)This I have already explain at this URLConfiguring Apache/Tomcat for serving Maximum number of requests
Security tweaks1. ServerTokens
This directive configures what you return as the Server HTTP response
Header. The default is 'Full' which sends information about the OS-Type and compiled in modules.
# Set to one of: Full | OS | Minimal | Minor | Major | Prod
where Full conveys the most information, and Prod the least, you can also set it to "ProductOnly" which is best
Optionally add a line containing the server version and virtual host
# Set to one of: On | Off | EMail
You can Set to "EMail" to also include a mailto: link to the ServerAdmin, better to set it to Off
This Allow TRACE method to enable/disabled
# Set to one of: On | Off | extended
Set to "extended" to also reflect the request body, best it to make it Off