Generally, it's boring to monitor the log of a proxy server. Unless something happen, I don't think the network admin will have interests to read those stuff.
Anyway, you can follow some guides:
1, Keep a good relationship with the network admin;
2, Don't visit sensitive sites, e.g. sex, political sites.
3, Don't visit non-working-related site when others are besides you.
4, Clear the buffer and history on your local machine everyday.