My two cents
Here are a few tips that can help you create quicker a summary of your presentations or reports:
Force yourself to use a one-sentence summary with three highlights
Use Q&A slides as titles for chapters and re-use them for the end summary
Put a visual bookmark (icon + bar) to signal key slides
Force yourself to use a one-sentence summary with three highlights
For some of my most complex research reports, I use a similar one-slide summary structure that works like this:
One sentence summary: I write the key learnings in one sentence. In this sentence, three keywords are put in bold and in colour and have numbers attached to them.
Three columns details: Below that big summary, there are three small columns where I give a title to each "keyword" that was highlighted in the one-sentence summary and add a few details in 2 to 3 sentences.
This structure forces me to think about what are the most important things I want people to remember.
Usually, I use this slide in the introduction as an executive summary and at the end as a recap'.
Use Q&A slides as titles for chapters and re-use them for the end summary.
For each title of a section in your presentation, use a slide that has:
A title structured like a question. For example: "What did we learn from the interviews with users?"
A short summary (or TLDR, too long didn't read) that summarizes the key learnings of the section. For example, write: "Users want: 1. Less waiting time, 2. (...).
Then at the end of your presentation, you can simply copy and past all your title slides (or the three most important ones) and you have a summary that took you a minute to create.
Put a visual bookmark (icon + bar) to signal key slides
You can use a visual marker, for example, a yellow rectangle with the word "Key insight" next to a hear icon to let people know that this is an important slide.
Then at the end of your presentation, summarize your presentation by copying and pasting all the slides that have this marker (or the three most important ones). Voilà.