[*] Tunneling out
Tunneling is fine, but remember that in the end it's still your packet, sent from your OS's network stack. Packet normalization could be used on a bouncing router and local router (only when being in "anonymous mode"). Also, make sure you block all the traffic going out of your host to anywhere but the TOR network.
Bouncing on several servers works only if the last one is sure to not be compromised and be the only one that can decipher the encapsulated packets.
For layer 2 tunnels, change your MAC address. Tunneling implementations can differ between OS and therefore expose/leak some information about you. Take care of this (see bellow).
- TOR cannot be trusted (really), so bounce before.
- The bouncing host should be a compromised box that you secured back. Make sure it's a busy webserver or other and assume it can be confiscated to be analyzed or spied on later on.
You could use a dummy VM inside your OS and use a pre-configured image that you replace before each use. This will ensure that even if your browser or application is exploited, no relevant information about you will be disclosed.
Everything you use in "anonymous mode" should only be used in this mode. On the same note, never check your facebook account or you emails or favorite website on this mode. You should cut it off from everything you are and you know. It's kind of like having a second life.
Using encryption and tunnels is suspicious, don't do it if you're under surveillance.
Also, stay low and don't attempt to commit crimes. If you really want to escape prosecution, these tips will only slow down classic investigation methods, you will eventually be caught, if you need to ask about more advanced strategies, you're already screwed.
[*] Real life
With all this, you might still be victim of a targeted attack by skillful remote attackers (who want to discover your identity).
And if you don't already know all this and more, you won't be able to achieve a perfect level of anonymity. If you are under an authoritarian regime and want to speak out using the Internet, you should go a step further and design stealthy protocols, use an optional HTTP header field to carry data to a server hosted in another country, this web server will sell potatoes or talk about dogs and let you tunnel out without being suspicious.
If you really want specific advice, I will need more details to give you an adequate level of anonymity. These were just basic things that people tend to forget or never use because it's too painful. But not as painful as being arrested for speaking out, or worse. It depends where you expect the privacy threat to intervene and how much you want to hide.