things to do after installing a new server


I am about to install second VPS based on 14.4 to host my site and replace my old 12.04.
I was just wondering what changes to the system should be done?

I read some articles that default Apache configuration sucks and that mysql can be tweaked.
Also does anyone use Xcache with latest php or is default caching ok?
Any special settings for either?

I thought of 1GB plan, but am thinking to go with 2GB plan, just in case my site gets hammered again and last thing I want is to miss a setting and get a system which is not optimised like it could be.