When there is no project open, you can view the Project Explorer window in order to add references that are used when compiling and linking the current file. These references are not inherited when you open a normal project. You could keep a long list of references and selectively include and exclude items using the Properties dialog for each reference. If you also want to configure your command line options then you can use a project "shell" as follows.
As an alternative to using the default project, you can create a special kind of project for general use. After creating the project, use the Project menu to select "Build Uses Active Source Only". This marks the project as a "shell".
A project shell is something between using a full project and not having a project open. When using the shell you can set command line options and references but the list of project files is hidden and cannot be used. When building, only the currently open and active source file is included in the build. Also there are no sub-folders for the various configurations and platforms.
A shell is particularly useful in a teaching environment. It can also be used when you need a "generic" shell for multiple projects, each of which contains only one source file.