Minor in Illusionary Arts

While studying at a prestigious college for wizards you took a few classes not directly related to your subject, and depending on what those studies entail grant you additional features 

Studying in the Illusionary Arts under Professor Madaleen

improved minor illusion: When you cast minor illusion you can create both a sound and an image with a single casting of the spell. 

when you cast an illusion spell that has a duration of 1 minute or longer, you can use your action to change the nature of that illusion (using the spell’s normal parameters for the illusion), provided that you can see the illusion. You can use this ability once per day.