Your speech focusing on Shakespeare's plays As You Like It and Cymbeline offer you a number of interesting opportunities for a comparison study. Firstly, you could examine the notion of hidden identities, in particular the notion of a woman taking on a false identity as a man. Another idea to consider is that of the parallels of pastoral tradition that exist in the plays and the theme of innocence as it relates to the pastoral tradition. A third possibility involves social commentary and critique, both of which are observable in As You Like It and Cymbeline.
An examination of hidden identities would allow you to compare and contrast the decisions of Rosaline and Imogen to take on the likeness of a man. In As You Like It, Rosalind is banished by her uncle, so she leaves only to encounter her beloved while disguised as a man in the Forest of Arden, while Imogen, daughter of King Cymbeline, disguises herself as a male figure named Fidele. This topic offers you a chance to explore topics around gender studies, patriarchy, and identity.
A speech focused on the pastoral tradition in each play might involve a close study of the connection between the countryside and innocence. As mentioned above, Rosalind is rejected by the court thanks to her villainous uncle, but she finds freedom in the Forest of Arden. Imogen flees to Milford Haven, in Wales, to escape the consequences of being falsely accused of infidelity. This topic can be related to the next one, as the authenticity and truth represented by the countryside could be a comment on the duplicity of city life, as represented by the court.
Finally, comparing the messages of each play in terms of Shakespeare's social commentary and critique of various societal habits could be a rewarding exercise. In both plays, family members betray each other and social class interferes with genuine connection between characters. A close look at the messages hidden in the art might reveal more similarities than differences from that point of view.