You can make your own references by bringing back phrases or pictures from previously in your writing (internal allusion) or by bringing them in from somewhere else (external allusion). Once you get the hang of it, it's rather simple. For example, if you were to write about a young man who dreams of becoming a baseball player but is too small to be drafted, you could internalize his desire by writing about someone who dreams of being a ballplayer but is too small to make it as a professional player. You could also externalize this idea by writing about a little boy who loves baseball but cannot play because he does not have a team or a field to go to. Finally, you could combine both ideas by having the young man travel around with his team while playing in different cities. In general, when you want to refer to something inside yourself or within your knowledge base, you should use internal allusions. When you want to refer to something outside of yourself or your knowledge base, you should use external allusions. And finally, when you want to refer to something that is both inside and outside yourself at the same time, you should use hybrid or mixed-mode allusions. Mixed-mode allusions are especially useful when you want to mention two things that are very close together but that also have some distance between them.