Very good advice! As an ex-freelancer who is very curious and loves to experiment and learn through side projects, the only advice I don't 100% agree with is "Showcase EVERYTHING".
I did that and it attracted a too wide array of customers and projects, mostly on topics that I didn't want to work on anymore.
As replying to potential clients takes time and saying no is not easy nor fun, I would recommend to pick a speciality / area of focus and/or a clear set of technologies you want to work with, and only share a portfolio that is related to that.
Also keep in mind that the projects that you take will influence the kind of potential clients that will contact you => only accept the kind of missions that you would accept to do again in the future.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.