My preferred body composition technique would be the Girth, Or Circumference measures.
Girths are circumference measures at standard anatomical sites around the body, measured with a tape measure. Girth measurements can be used in determining body size and composition, and to monitor changes in these parameters.
I chose this as this technique is relatively cheap, and it is very convenient to perform at home, which allows for proper tracking of the body. In addition, when performed with the skinfold measurments, a clearer picture of changes in muscle and fat compositions and distribution can be seen.