Step 10: Draw a C-shaped line inside BB-8's body, above the horizontal line, for the base of the lighter. Add a small circle within the C-shaped line. And draw two lines to the left of it for the rod that holds the lighter. These two lines almost reach the edge of the body. Sketch them lightly at first to get them right. Add two more lines that are closer together for the tip of the rod that holds the lighter. You can also skip the steps for the lighter if you want a simpler version of BB-8.
Step 11: Draw another set of circles at the end of BB-8's rod for the lighter's gear. Add a curved line over the gear and a tiny circle on top of it for the lighter's base. The acutal flame is made up of two wavy lines that come to a point at the top.
Step 12: Now draw the opening on BB-8's body where the lighter and rod are coming from. Follow the vertical construction line as you draw the right side of the opening. Draw the top part of the opening using a series of short lines. Don't overlap the lines for the lighter. The shape is a bit tricky, so use the image above for reference.
Step 13: Draw BB-8's metal flap that swings open to the left of the last shape. The shape of this flap is basically the mirror image of the opening from the previous step. Add a few squares within the shape of the flap for extra detail.
Step 14: Draw a circle inside BB-8's body, on the top left side, surrounding the opening from the previous steps. First draw four marks for the circle's height and width, then connect those marks using curved lines. Use the construction lines to help you correctly place the marks that indicate the height and width of the circle. Sketch the circle lightly at first. When you get the shape right, darken the lines.