Exporting a PDF for my Kindle always feels like I'm preparing a document for a road trip. It's not just about the file itself, but how it'll behave on that smaller screen. My go-to method is using Amazon's Send to Kindle service. I'll go to the website, drag the PDF in, and let them handle it. It's reliable for the basics.
However, if I want more control over the layout, I've had mixed results with automatic conversion. Sometimes the text reflows nicely, other times it's a jumbled mess of footnotes and columns. For anything with complex formatting, like a technical manual or a graphic novel PDF, I'm starting to think a tablet might be a better fit. The Kindle really shines with simpler, text-heavy documents where you can adjust the font size without breaking the page.
Calibre is the tool I'll open when I need to get serious. You load the PDF, convert it to AZW3 or MOBI, and tweak the settings like margin correction. It's not always perfect, but it feels less like magic and more like a craft.