For: Male & Female Models
When choosing images from your shoots, stick to the best 1-2 shots per look. Translation: if you have 3 outfits, that means you have 3 "looks." By the time you're done going through all the photos, you should have at least 1-2 of your favorite images for each outfit/look you've done...so that would total 3-6 images.
When it comes to portfolios, you should not have a bunch of photos with you wearing the same "look." It may be hard to decide but you want diversity in your portfolio and that can't be achieved if you have 5-6 pictures with the same outfit on.
Having trouble narrowing it down? If you just can't pick 1-2 final images from a shoot and instead you have 3-4, then consider putting together a collage or having a 2-in-1 photo instead.
Below is an example of 2 photos that were combined into 1, which would count as 1 shot for your portfolio:
Below is an example of 3 photos that were combined into 1:
Below is an example of 4 photos that were combined into 1:
I think you get the idea. :-)