Depends upon what 'project' the project dir is for. As for format, mostly just plain text files, except for where other formats are necessary (i.e., datasheet

Depends upon what 'project' the project dir is for. As for format, mostly just plain text files, except for where other formats are necessary (i.e., datasheet pdf's for a hardware project dir, etc.). Various sub-directories as needed for organization. Meaningful names for most files/directories.