Using games in a portfolio

One of the more common things I see people say on this subreddit is to finish your game and get it on steam so that you can at least use it as a portfolio piece if nothing else.

I’ve finished my first game and have had it uploaded on steam for two months now. I’m working on my second game now, but I’d like to see if I can work with a studio for my next game after this one. Only problem is I’m having trouble thinking about how to present my games in a portfolio. I’m used to the traditional resume route for getting a job (since I’m just now getting into a creative field) so I’m a little unsure about how to go about it.

If you guys have any tips or methods for presenting your work to studios I’d love to hear about it.