Agree re not binding or using paperclips.

Re articles - I'd name the mags/newspapers, but I reckon it's ok to just mention the area you write in, if if you've had a lot of features published - for example, 'I write travel features for The Guardian, The Financial Times and The Observer.' or 'I write health and beauty features for Grazia and Closer.' - rather than listing the particular feature titles.

Re age...I find it's good to be a bit vague about that initially...I write for a twenty/thirtysomething market and don't exactly fall over myself to let on that I'm 42.

You probably know this, but make sure there's a footer on every page with the page number, book title and your name on it. Unbound papers can be dropped!

Since this thread started, the splendid Nicola Morgan has published a really cracking e-book, all about the whole submission package stuff:

https://www.nicolamorgan.com/publishing-advice-books/dear-agent-write-the-letter-that-sells-your-book/

Highly recommended!

Yes, Nicola Morgan totally brilliant.  Good luck!