If you are one of the lucky few to be taken on by a major agency, you do not need to worry about this question. Your agency will produce your first promotional shots for you (which should not cost you anything). After that, your portfolio will consist mainly of tear sheets.
For the purpose of this page we are talking about a model at the beginning of her career, either with a smaller, local model agency or working freelance.
Cheap and instant digital creation of images has made it possible to supply hundreds of photos relatively easily. I still come across aspiring models who boast about having received 100, 200 or more images from a shoot, paid or TFCD.
Receiving a very large number of images may make you feel important and it may impress your mates - and that's just about it. No photographer or agency wants to look at more than a handful of photographs. They do not have the time. Besides, once you have seen five headshots of a model, you have seen them all. After that, it is all repetition.
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As your career progresses, you will have a larger selection of unique photographs to choose from and you may want to compile a showcase, which serves an entirely different purpose.
For a portfolio, think quality not quantity. Ten or twenty strong, unique photographs will serve you much better than fifty or 100 mediocre ones.
You can reasonably expect to receive a minimum of twelve images. For a beginner's portfolio, aim to have between 12 and 24 images in your portfolio.
Ask the photographer to put together a small selection of the best photographs from a shoot. You do not have the experience or the expertise to make that choice from a large selection.
Consider the potential shots for your portfolio side-by-side. Every photograph should be different, unique and memorable. Avoid repetitive poses, facial expressions and set-ups.
When building your first portfolio, do not use photographs from only one shoot. Aim to work with different photographers. The different styles will demonstrate your versatility as a model.
You want a combination of headshots and half, three quarter and full length shots.
Whether you need nude shots in your portfolio is discussed here.