Presentation Mode
Presentations are a great use case for Typst, be it with a hand-rolled template or using a package like polylux or touying. The strengths of a markup- and automation-based approach come to light especially when you're reusing content across a presentation and a report.
With Typst Pro's built-in presentation mode, you can give your next talk right from the Typst app.
Presenting
When Typst detects a 16-9 or 4-3 page aspect ratio, it will automatically display the 
"Present" button next to the "Share" button. Alternative, you can start presenting a document with any kind of aspect ratio via "View > Present" from the menubar. To leave the presentation mode, click the large red 
button or press Escape.
By default, Typst will display the presentation on your current monitor in full-screen mode. Alternatively, you can click the dropdown arrow next to the "Present" button and select "Speaker Mode". Now, the presentation will open in a separate window, which you can fullscreen on a display of your choice. The main window will then display the Speaker Mode. To switch from Speaker Mode to in-tab presentation, select "View > Show presentation in this window".
Speaker Mode
The Speaker Mode is your control center during the presentation. On the left side, it displays the current slide and at the bottom controls to navigate to the previous and next slide, to highlight and draw on the slide, and to temporarily hide the current slide. On the right side, it displays the upcoming slide, the current time, and for how long you've been presenting. The green bar at the bottom indicates how far you've progressed in your presentation.
Moving through the slides
You can move to the next slide by clicking the left mouse button or pressing the right arrow key. To move one slide back, click the right mouse button or press the left arrow key.
The timer
The right panel show the current time and a timer indicating how long you've been presenting. If you've been preparing for a bit, with speaker mode already open, you can click the 
Reset button to set the timer back to zero right before you start to present.
Highlighting with the laser pointer
To highlight something on the slide, you can use the built-in laser pointer. Select 
"Pointer options" in the bottom left toolbar and then "Laser" or press L to enable the laser pointer. To disable the laser pointer, select "None" from said menu or press L again.
Drawing on the slides
To draw on the slide, select "Pointer options" from the toolbar and then "Pen" or press Shift+L. In the "Ink color" menu just below, you can select from different colors for your drawing.
You can now start drawing on the slide. Your drawings remain in place as you navigate to other slides, but are cleared once you leave presentation mode.
To clear drawings from the current or all slides, select the corresponding menu entry from the "Pointer options" menu. Note that it's not currently possible to erase drawings more selectively.
Lights off
The 
button in the bottom toolbar (or the B key) temporarily hides the presentation from your audience. In the Speaker Mode, the slide contents appear dimmed, but you can continue to navigate in your presentation, to find just the right place for turning the lights back on.
Speaker notes
Currently, Typst's presentation mode does not have a facility for speaker notes. This is planned for the future.