Transforming your classroom into a mini-conference takes a bit of planning, but it's well worth the effort. For my graduate ethics course, I have been slowly adding more conference-like attributes each semester. You could do this for almost any level of course, with any student presentations. Students can get an introduction to conferences in a low stakes environment.
Our conference was Ethics beyond Utilitarianism: 2018 Case Study Conference, where panels of four students presented their cases in 5-8 minutes, with about 15 minutes left for Q&A.
Room organization - If you're lucky enough to be in a room where furniture moves, organize your tables for a panel presentation in the front with audience-style seating for attendees.
Program - Ask students for the names/topics of their papers or presentations ahead of time. Work those into a program with three or four students on a panel. Print hard copies of the programs to hand out as students enter the conference.
Roles - Seek volunteers for moderators and discussants — or assign these conference duties to students interested in attending other conferences. Add their names/roles to the program. Remember to give students a short primer about these roles and expectations. Explain the role of the audience to ask questions, and when and how to do that.
Publicity - Advertise your mini-conference to your department head, colleagues and other classes meeting at the same time. Outside attendees can make it feel more like a conference, and students can share their findings with a larger audience.
Debrief - Be sure to explain the conference experience after each panel finishes. You are essentially using your class as a conference simulation. We talked about how to facilitate networking following your presentation, adding your social handles to your presentation or nametag, how to handle wonky questions from the audience, and the awkwardness of being in front of the crowd while the other panelists present.
Individual feedback - After the conference, I emailed individual feedback to each panelist.
In the future, I want to incorporate live video feeds and answering questions from virtual attendees. My hope is that more students will consider submitting their work to a conference because they have had a small taste of the experience.