I have used Scribus in the past, but I was not entirely satisfied with it.
What do you use to make PDFs that is intuitive and does not have a steep learning curve?
Then, as others have suggested, Print > Save as PDF.
If I require the PDF to have editable fields, I then use Adobe Acrobat Pro. Fairly easy for simple use cases. Not sure of the cost on that.
At the end of the day, now I'm optimizing for simplicity. Personally I use Google docs, but open office would be exactly the same. You just print as PDF when you need the PDF -- and with Google docs typically you can just share the link in view only mode, you don't even need the PDF.
The reason for me is small edits. With Gdocs I can do any small change even on my phone, and most importantly I can share the file with anyone and they can make edits for me, if needed.