I love using my iPad for travel to conferences, and not just because it's so lightweight and its battery lasts all day. For one thing, with the LTE version I'm not beholden to conference Wi-Fi; while some conferences have good connectivity, I never want to count on it. With the iPad I can nearly always get online.
But the iPad isn't convenient only for attending conferences. It's a good tool for presentations, too-or at least an excellent backup for a dedicated computer. I can easily be ready to present if I have a last-minute computer replacement.
Still, I had some things to learn the hard way about using an iPad for presentations. Perhaps I can save you a few steps.
While I present nearly exclusively from an iPad, I usually build my initial presentation on a Mac. I build all of my presentations in Keynote, and store them in iCloud. I can (and do) make tweaks to a presentation on-site via the iPad version of Keynote, but it always feels as though I'm slightly fighting with the software.
Keynote supports a customizable presenter display in both versions. On the Mac desktop version, you can pick three ways to give yourself that during-the-talk cheat sheet, instructing it to show you the current slide, next slide, and presenter notes. On the iPad, the presenter display options only give you a "two out of three" option, between current slide, next slide, and presenter notes. I begrudgingly pick Next Slide and Presenter Notes, and then I hope the venue has a confidence monitor that shows me what's on the projector behind me.
Do be aware that this means that if your presentation requires a demo in a terminal or a web browser, you either get to do some awkward transitions—or accept that presenting from an iPad isn't right for this talk. I still haven't found a good way to give my "Terrible Ideas in Git" talk from an iPad due to its live demos...
A presentation remote is a necessity, unless you enjoy being trapped behind the podium. I treated myself to a little luxury with the Logitech Spotlight.
This device does it all. It speaks its own wireless protocol via a USB-A dongle that plugs into most laptops, but the Spotlight also speaks Bluetooth with a great range. Its battery charges using a built-in USB-C port that hides behind the dongle, and a single charge lasts for months.
I freely accept that most folks find the idea of paying $129 for a single-purpose device a bit nutty. Those folks generally don't give double-digit numbers of presentations a year. A word of caution: Don't leave it behind at the podium after your talk. It's expensive enough to buy the first time. Please don't ask me how I know.
I have a condition I jokingly refer to as "typeface blindness." I can't tell the difference between most fonts unless I stare at them and actively work out what I'm seeing. I'm told this is atypical, and whenever I forget this fact I get reminded on Twitter. "Well, that's the fifth talk so far today that uses Helvetica (the system default)" always makes me facepalm. As a result, I make it a point to not use system default fonts.
Contrary to what many folks believe, you can use custom fonts on iOS, but the process is a bit arcane. Do yourself a favor and drop the $2 for AnyFont. This magic app streamlines an otherwise incredibly painful process.
I'm conservative here; while you can save money by buying third party adapters, I find that minimizing the risk of screwing up a presentation in front of 400 people is worth the extortionate rate that Apple charges for first party adapters. You'll want both HDMI and VGA adapters. Both of these are available in Lightning and USB-C flavors, depending upon which generation of iPad you're using. Note that this is less of a concern with USB-C than it is with Lightning adapters---just make certain you test all of your adapters before you leave home.
Save time; don't bother looking for DVI adapters. The iPad officially doesn't support it, Apple doesn't sell them for Lightning, and I've only ever encountered it on the speaking circuit once. Your test a few hours before your talk will validate that you'll be okay.
Grab a beefy battery pack, and you can go days without finding a power outlet. You don't want to discover that the podium power strip is full, the extension cord is a trip hazard, or that you don't have the right adapter for the country you're in when it's time to give a talk. Having a battery pack that can borderline jump-start a car means you're fine so long as your iPad battery level is anywhere about roughly 3%. (Too much lower and the tablet won't boot at all.)
I like Anker products for this, but your mileage may vary. I soundly endorse finding reputable brands. Saving a few bucks on chargers, cables, or batteries that (a) plug into a very expensive electronic device and (b) have a propensity to include "sets the building on fire" in their list of failure modes just never seemed worth the trade-off to me.
Note: If you need to give away something at a booth, don't use branded USB battery packs or chargers, as swag. At best, they're cheap and feel flimsy. At worst, something with your logo on it started a fire.
You can tether your iPad to a mobile device or ride on conference Wi-Fi. However, if you're presenting frequently it's worth the extra money to get an iPad version that can speak to the cell networks. Suddenly you no longer care what the conference Wi-Fi password is, whether you remembered to charge your phone, or if the captive portal login page is going to expire and pop up again mid-presentation.
Speaking of which...
In presentation mode, Keynote swears that it blocks pop-ups, reminders, incoming calls, and other distractions. To its credit, I've never seen it do otherwise.
That said, I always enable Do Not Disturb on my iPad. I put the device in airplane mode. And only then do I plug in the projector. Perhaps I'm paranoid, but you're also not seeing horrible screenshots from my talks that feature embarrassing notifications, either.
If a new iOS version or a Keynote update comes out the same week as your presentation, fine. But resist the upgrade. It can wait a day.
There have been enough regressions in software over the years that I'm extremely hesitant to trust that everything will "just work" an hour before I go on stage.
These are the sometimes-hard-won lessons I've learned after spending a year giving talks solely from an iPad.