To create a custom masterpage, you can either copy the default.master and rename it and work backwords or you can create it from scratch using a basic/minimal masterpage.
The publishing masterpage's that I came across are from Heather Solomon blog and the other which I follow is from microsoft.
Both of them have default content placeholders. Either hide or use them in the masterpage
Mirosoft's minimal master page
Heather Solomon's base master page
