In my opinion, 'style' just happens; you will discover it when you look back at your work over a period of time. You'll suddenly notice that you like certain colors a lot, or that you really prefer the work you do in one medium over another or one subject matter over another. I used to fret constantly about this style issue, liking everyone else's and not seeing that I had a valid style as well! In fact, in many ways it was one of the biggest wastes of time, worrying about needing a style.
My best advice is to try everything (medium, materials, technique, color palette) that appeals to you, like clothing. The items that suit you will stay in your closet, you'll discard the ones that don't, and sooner or later you'll end up with a particular wardrobe that is uniquely your own. It'll happen when it happens, and it happens by pursuing your art practice on a consistent basis and with intention.
The reality is, you need to be able to like to produce your own art even when it's not trendy, and there's a lot to be said about continuing to experiment. Artists are often afraid that by doing this they will lose collectors, but really, you can keep your work fresh without losing the basic components that make your work yours. And it's important to have fun, to try new things, for your own sanity! Try some new colors on your palette. Try a few different brushes, or add a new technique in with those you already use. A new body of work will pull you out of any rut, and even if it's not as successful as your other work you will have learned great lessons in producing it. This is how you grow as an artist.
And in any art museum, portraits are everywhere: in every style, color, and size, from every country and created by every type of artist.
In a portrait's brushstrokes we find a path connecting us to another human on a timeless level.
Da Vinci's Mona Lisa, van Gogh and Rembrandt's many self-portraits, these are just a few of the well-known portraits that have come down to us through the ages. Their popularity is testimony to the power and value of capturing personality, character, and aspect, on canvas.
Oil paint captures the living qualities of the human face and body like no other medium. Skillfully handled, the portrait transcends technique and draws the viewer in, and a single artist creates a treasure for us all.