Any basic search within the Bitcoin community and you'll find many many guides and services for Bitcoin money laundering:
https://old.reddit.com/r/CryptocoinMixing/
https://bitcointalk.org/index.php?topic=436467.0;all
https://darknetmarkets.org/a-simple-guide-to-safely-and-effe...
https://ethereum.stackexchange.com/questions/2699/is-there-a...
Vitalik Buterin himself has attempted a money laundering feature into the Ethereum Virtual Machine codebase: https://github.com/ethereum/serpent/blob/develop/examples/ec...
Another famous way to launder money as described in this post from a moderator on BitcoinTalk dated August 22, 2013, 02:32:31 AM [ https://bitcointalk.org/index.php?topic=279249.0 ] , is to give Bitcoin to a mining pool in return for renting their hashpower, in return for freshly minted coins: