although this is about search, still its good practice when dabbling with multiple accounts from paid traffic source, facebook, adwords, bing etc..
- when managing multiple accounts, do take special care
not to accidentally reuse domains in old banned accounts in the new one.
this has bite me a few times when i forget to do meticulous tracking of what
im running where and reused past domains from flagged accounts. (juggling many domains/accounts leads to slipups
)
- do not accidentally switch ips while logged into your account.
anyone got anything else to add, feel free: 
Don't share credit cards between accounts.
Everytime I create a new account I make a note of the following in my Workflowy:
account name
email address
CC
billing address
cell# used to verify the account
the VM I used (change default device name under system properties)
OS (Win7/XP/MacOSx)
browser (oldapps.com)
domains used for landers/tracker (+ their unique IPs)
niche (like coreg/dating/etc)
+ my broadband comes with dynamic IPs, so I make sure I reset my modem everytime I login to an account
This helps as long as the users don't complain about your ads.
Good info.
Make sure any domain you buy for use with the accounts has WHOIS protection too. I'm not sure whether Google checks, but if Google is capable of checking, it needs to be worked in to your checklist just in case.
I'm grateful I've only had one Google account banned. The process of effectively becoming a new person is a major pain in the arse.