"Everything must serve the idea. The means used to convey the idea should be the simplest and clear. Just what is required. No extra images. To me this is a universal principle of art. Saying as much as possible with a minimum of means."
David Bayles, in "Art and Fear", has an interesting take on style. He says that style is a result of the many little habits we develop as we progress with our work. How we mix our paint, where we hold our brush, the shape and size of brush, what colours we put on our palette, are all examples of little habits that lead to a style. Style is inevitable, we can't NOT have a style. So just do your work and you will have a style.
I had painted in acrylics for about 10 years when I decided I wanted to paint in a much looser, painterly "style". So I changed my medium to oil paint and brought all new supplies - brushes, supports, paints - everything. I even sought out new instructors to learn from. I was successful in developing a new approach to my artwork, but anyone who was familiar with my older acrylic stuff immediately recognized my work in the new medium. They said it just looked like my stuff. Style is a part of how you deal with the world and your own nature and it touches everything you do - including art!
The truth will set you free,
but first it's gonna piss you off!