Some people give gifts at this time of year, I prefer to give presentations. Well, I like doing it at any time of year really; but I thought I ought to try and make some concession to the time of year.
At most conferences I go to, I end up giving a presentation (and no, that's not just because you can sometimes get paid to attend if you speak) and so I've tried most of the Linux-based presentation tools over the years. I'm sure there are new ones I haven't yet encountered, but I thought I might include some of the ones I've been at least marginally successful using. If you are wanting to give presentations from a Linux laptop then you might find the following useful.
Things I've used
If you're used to "traditional" "powerpoint" "presentations" then you will likely find Libreoffice's presentation tool to be very easy to get used to. It is quite easy to get basic presentations going with relative ease. It is not, however, very modern in its presentation design, which can result in quite dated-looking slides.
If you prefer a simpler looking presentation style then you might enjoy the Pinpoint from the Gnome project. Pinpoint is a very simple presentation tool which focusses on providing simple slides which look clean, and making it nice and easy to manage your presenter notes. Unlike Libreoffice, Pinpoint's input is a plain text file which makes it much easier to version your presentation in Git.
PDF Presenter Console
If, on the other hand, you prefer to generate your presentation in some other tool which can then output a PDF; then pdf-presenter-console may be for you. It takes a PDF (and optionally some presenter notes) and provides a multi-screen presentation tool with presenter notes. You can edit your notes in the tool if you notice problems during your test runs, and it's a good example of doing one thing and doing it well.
Things I've not used
I know various people who use Pandoc combined with [slidy] or even write
their own LaTeX with beamer or similar. Personally I think that if I
used those, I'd then want to use
pdf-presenter-console to give me speaker
notes capability though a PDF with no notes is a useful way to have a
presentation which is easy to transfer to other computers.
As an alternative to slides, some people prefer to type messages on the fly. To do this you can use screen-message which displays text as large as possible as it is typed. This is useful for when you improvise a presentation (or want to make it appear improvised).
A few tips
If you're new to presentations then it can be very tempting to fill your slides with useful information so that you feel like your audience will get a lot out of your talk. This is a bad thing™ and you shouldn't do it. In fact there's so much useful out there about how to give presentations that I'd suggest you go and look at things like this.