Stay sharp! Good quality pencils will allow the lead to be sharpened regularly. Needle sharp tips on your pencils are perfect for applying detail and getting the precision required to color intricate areas of a design. Thinner points will give you more control over the color produced, big fat rounded ends on your pencils make it difficult to get the brightest colors.
Professional level pencils like Derwent or Prismacolor offer the best quality and typically are the most expensive pencils to buy. The wax in these pencils is softer and the colors are a higher pigment providing brighter colors. The soft application allows blending and shading.