Remember also when you're using SSH socks proxy that all your DNS requests go through the un-proxied connection -- unless you're using Firefox, in which case you could set network.proxy.socks_remote_dns to 1 in about:config.

Another point is that most firewalls block most ports, but usually not 443 (https). So set up your SSH server on port 443. Since all traffic to 443 is encrypted anyway, you're less likely to raise suspicion.