I don't use many tools, but this is what I use regularly:
My first step in starting a piece is picking an image. Once I have one of my photographs from my camera roll selected, I pick the size of stretched canvas I want and begin with an underpainting of a color, usually the complementary color to the dominant color of the photograph. I print out an image on paper to scale with the canvas and then once the underpainting is dry, I grid both the reference and the canvas. Then, I use the reference and grid to draw the image at full scale on the canvas.
Once the image is drawn on the canvas, I use a glossy reference image for color to paint the piece. I work from background to foreground, usually doing the sky first. I started doing this when I painted a piece that had water and a railing. I had painted the railing first, and I had to paint the water in little chunks inbetween. This didn't look that nice to me, so I have since always painted continous things all at once and then painted anything crossing over it afterward.
Here is an example of how I proceed through painting a piece. I like to work from background to foreground, and I prefer to make sure each part is finished before I move on to the next.
Here is another example of how I proceed through painting a piece.