I have some cool visuals to do with process of developing an end idea or product, but I was wondering how much process I should show in my portfolio.
I think in general the answer depends on where in your career you are.
Early in your career, (good) recruiters may be even more interested in the process than the end results: your skills will improve quickly on the job, but if you don't know how to go about developing ideas, understanding client's needs and making it all work, that's much harder to learn as you go. So, two or three or more good examples of working process may be a good idea.
Later in your career, it'll be much more about the end result - so it might seem odd to have examples of working process unless it was an exceptionally interesting process (example).
Mid career, it'll be somewhere in between.
In general, showing working process is a great way to show off potential - but naturally means you have less time and space to show off actual completed work. They're also good for showing depths and difficulties in a project where the deceptively simple-looking clean end result hides a huge amount of difficult-to-balance requirements.
Add process related stuff where you feel like you have potential and ability beyond the actual output of what's in your portfolio. To me, process examples in a portfolio say "I made these things, but look at this - I'm capable of so much more as well!". So the amount depends on how much you want to say that, against how much you think the end products speak for themselves.
Just be careful that the presentation of the process is simple, clear, clean, and shows how that process led to this end product. Be particularly careful with examples of process in student work or unusual projects - if it's really off the wall or far removed from the day-to-day reality of wherever you are trying to work, it might put people off.
In your actual portfolio, I would suggest almost never showing the process. A portfolio itself should be about final, completed works in as simple and elegant manner as possible.
What many designers and agencies have done, quite successfully, is merge the concept of a portfolio and of a case studies in one. If you have the time, and a collection of clients that you've had a positive interaction with, I would create a full case study gallery. Many designers call this a "Portfolio", others call them projects, "view my work", case studies, etc.
This can include, but not limited to:
It's really just to highlight the entire scope of the work you do, and that moves on beyond just process imagery.
Here's a few examples:
A lot of them are more image-centric, but they generally highlight more than just a few screenshots.
Always show process. As much as you can/feel appropriate.
For a portfolio to work for a design firm--they'll absolutely want to know about your process. For a portfolio for getting clients, they may not be specifically looking for your process, but in showing it, you will help communicate your broad skill sets and what you are actually providing the client (a complete process rather than just 'some quick art').
Show everything you feel is relevant but make sure the final piece dominates.
Just make sure that your process is clear and structured. If you tend to be sloppy and disorganized during the development phase, showing that can create doubt about your ability to stay on task. In that case, you'll just have to judge your audience.
In the end, you want the process to feel integrated with the whole story of the project. Does it show your creative development clearly; help explain your communication with the client; reinforce your commitment to business goals over "just playing around"? Make sure you have a good story to tell, because a seasoned designer will have questions.