It mostly depends on what do you mean by "detoxifying", but if you would like to simply clean your system its good idea to try to stay in a clean enviroment, as much as it is possible - parks or nature in general is great. Also try to cut any junk food and eat more fruit and vegies. Light exercise is also a good idea. Nothing too extensive, but if you will be in a park try to walk instead of sitting.
Find something to think about. Something that will drive your brain. Making your brain to function better is also part of detoxifycation, since it will become more effective in solving problems.