The entire premise behind a portfolio is the opportunity for you to present your work to potential clients. It's a vital component for you as a photographer and the most taxing part of creating one is selecting your absolute favored shots since there's generally a temptation to want to include everything to demonstrate how diversified you are in capturing various subjects.
There's a lot of great resources online as well as tangible books to assist you with the process of building a strong portfolio that you can be proud of, all of which I've merely glanced at because I've never really felt the pressure to compose one.
I shoot mostly for myself without any real motive to get rich doing it which in return offers me the liberty to dedicate as much time to subjects that deeply interest me without feeling that I'm wasting time because I'm not "marketing" myself.
If someone's interested in viewing my work, I direct them to my website/blog hoping they would walk away with an insight of what I like via the imagery and words I publish.
On that note, during arranged outings, I try my hardest to limit variety in my shots and keep it somewhat consistent with the type of work I want to be known for. While a macro shot of a grounded bumblebee on a sunflower may seem attractive, you're very unlikely to see me ever publish these type of photographs because I don't think they're indicative of who I am or what I like to capture.
Normally I'll share a brief backstory to every photo I publish but I'll retain myself on this one because if I chose to photograph a person rather than many of the other intriguing sceneries or details one could potentially come across in a setting like Chinatown, mostly likely you'll get an understanding for what wins me over all the time.