% Declaration of options
\def\my@package@stuff{}

\DeclareOption{acommonoption}{\xdef\my@package@stuff{\my@package@stuff,acommonoption}}
\DeclareOption{apackageoption}{\xdef\my@package@stuff{\my@package@stuff,apackageoption}}
\DeclareOption{anotherpackageoption}{\xdef\my@package@stuff{\my@package@stuff,anotherpackageoption}}
% Execution of options
\ProcessOptions
% package loading

% main code
\def\showpackagestuff{\par\noindent Package options: \my@package@stuff}