I usually have a hard copy portfolio and a portfolio on my Ipad, (there are many Apps out there which provide a lay out for this). I usually take both with me as I think CAD work looks better on the Ipad and can be zoomed in to look at the detail, but I think a lot of employees like looking at something physical in their hands. So you can pick out, say your best for printing then have the story or the bulk of that design in your Ipad should they wish to look at it.
Also with picking images, pick ones in which you can talk about, you don't just want a finished product in your portfolio you want, you want sketches of ideas, or CAD work behind your product.
In my physical portfolio I have the following:
At the start an overview, so this will be 10-12 of my best images including sketches, a trend board, an inspiration board, CAD drawings of lingerie and if possible on the corresponding page the finished garment so they see what it look likes start to finish, a press piece and a couple of pieces tailored directly to that company.
Then on the following pages everything is date/season ordered and in categories so lingerie/swimwear/kidswear and also extra categories such as Press and also a Technical section. The technical section section would include hand grading, computer grading, tech pack layouts and spec sheets. At the start of my career this would more important than now as having been in the industry so long it's a given that I should know all that stuff, but when I was first starting out I needed to portray that I knew and understand that side of the industry. Now the technical side would include specialised sections such as knowledge in the bigger cup section, and grading of complicated lingerie designs, basically anything that includes specialised knowledge that not everyone would have.