Offer fun toys. Tummy time is great for your baby's development. Provide bright, stimulating toys in front of your baby to encourage him/her to explore the environment. Talk to your baby and encourage frequent periods of tummy time daily. It appears that stimulation to your baby's hands may has long term benefits more than helping to turn over (such as helping with handwriting & fine motor skills later in life!).
Place toys around. Make sure there are bright objects or stuffed animals all around the baby's possible viewpoints. That way whichever direction your baby looks there is something interesting to look at. Also, keep tummy time to a minimum at first when your baby is getting used to it. Gradually increase the time as your baby begins to have more fun.