how can i do Best optimization for my.cnf

i have vps run cenotos 6.5_86_64 16G off ram 1 TB HDD

i use it for webhosting
and i have a forum vb 3.7.5

now i receive more messages like this

mysql_connect(): Too many connections

please helpe me for best configuration for my.cnf

original file

 

Hello,
To fix your Too many connections issues, you need to increase your connection limit in my.cnf file.

For the optimization, I will suggest you please have a look at http://mysqltuner.com/