Typically, Accounts are broken down into segments (eg, Country, product, department, class, etc).
For example, a cash account could be 00 (US) - 11000 (bank) - 00 (default) - 00 (default)
IF you have multiple bank accounts, then it would be 11001, 11002, 11003, etc. If they are in different countries, then you can change it to 01, 02, 03, etc.
The Chart of Accounts itself can be broken down into sections. Eg, anything starting with a 1 (eg, 11000, 15000, 19000) could all be current assets. 20000 - 29999 could be fixed assets.
30000-39999 - Liabilities & equity.
Within each section, you can break it down. EG, AR could be 12000, US Ar could be 12010, CAD AR 12020, etc.
I know this was quick, but I hope this helps. If you want to take this as a starting point, you can post your proposed Chart of Accounts, and we can provide additional feedback.