I'm have promarily used Subversion in the past, and the structure we used was:
/branches - Self evident name for branch management
/int - Integration branches
/projectA_effort_q4_2014 - Integration branch for release on q4 of 2014
/usr - Individual engineers branches
/fred - Fred's set of branches
/some_bug - Fred's branched from somewhere to fix some bug
/sally - Sally's set of branches
/some_feature - Sally's branched from somewhere to add some feature