Massage and stroking of the upper and lower back can be stimulating and very enjoyable. Vary between light and firm pressure, and dry or wet touching. Use massage oil for less friction but remember to clean your hands before applying a condom as the oil will damage the condom. For something different, try using ice cubes or feathers.
Hold and stroke the back during woman-on-top or sitting positions. Have a look at our Gourmet sex section to learn how the back can be stimulated during Tantric sex or Kama Sutra.