I assume, for convenience, that you're using Firefox on Linux. It should be relatively easy to adapt these instructions to different browsers and platforms. I also assume you own a box you trust somewhere, on a connection you trust to some degree (i.e., a wired connection). I'll call this your "trusted machine". (In my case it's a box that sits in my apartment and acts as a fileserver, among other things.) This is a hard requirement.
Also, I prefer to stay on https whenever I can, so I use the EFF's HTTPS Everywhere extension. This will redirect you to https versions of sites when you navigate to plain-http versions.
Setting up the SOCKS proxy is extremely easy: ssh(1) can do "dynamic" application-level forwarding (i.e., SOCKS):
$ ssh -D localhost:1080 -N trusted.box
Now you're listening on localhost:1080 (or whatever other port you choose), which can be specified as your SOCKS proxy. In Firefox, go to: Preferences -> Advanced -> Network -> Connection -> Settings -> Socks Host, and enter hostname "localhost", port "1080" -- not "HTTP Proxy" at the top, like everyone does the first time.
That's a pain in the ass, however, because you have to re-establish the ssh tunnel every time you lose your connection. autossh is the solution.
Make sure you can log in to your trusted machine without a password, otherwise autossh won't be able to automatically reestablish your connection. Either use a private key without a password, or, preferably, an ssh-agent. (keychain(1) is useful for making ssh-agent more convenient. Getting a comfortable ssh-agent environment is probably the most tricky part of this, but the payoffs widespread when you get it working.)
Now, instead of the ssh(1) command above, run this:
$ autossh -D localhost:1080 -N trusted.box
autossh will reestablish the connection when it fails. I have a tiny shell script called 'tunnel' which just runs the above command.
For added convenience, install something like QuickProxy to easily enable and disable the SOCKS proxy.
[Edit: Chrome can be set up to use the proxy like this:
google-chrome --proxy-server="socks5://localhost:1080" --host-resolver-rules="MAP * ~NOTFOUND , EXCLUDE localhost"
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