Whether you present your work to a few close colleagues, to a large scientific audience at an international conference, or to a group of non-scientists at the local theatre, the design and delivery of your presentation may need to be adjusted to accommodate the audience. The aim of the current chapter is to provide you with some tips on how to do this. We will do so by differentiating audiences on three characteristics: small versus large audiences, national versus international audiences, and scientific versus lay audiences. This chapter will address questions such as: How much prior knowledge of the subject can you expect your audience to have? What is their primary goal for attending (e.g., to learn about your work, to learn about you, or to obtain course credit)? How fresh or tired will your audience be? The answers to all of these questions, and many more, may impact the effectiveness of your presentation, and are therefore important for the preparation of your presentation.