Draw a number line. Make sure both numbers in your inequality are included in the number line, and continue it beyond those numbers. For example, in 3 < x < 8 you could have points on the line labeled from 0 to 10.
Draw a circle at the larger of the two numbers in your inequality. In the example, draw a circle at 8.
Determine if the "less than" sign adjacent to the larger number is a "less than or equal to" sign. If it is, fill in the circle.
Draw a dot at the smaller of the two numbers in your inequality. In the example, draw a circle at 3.
Determine if the "less than" sign adjacent to the smaller number is a "less than or equal to" sign. If it is, fill in the circle.
Mark the number line between the two circles.