More lather time
Many over-the-counter shampoos will help with a flaky scalp, including selsun
blue, head and shoulders, t-sal/t-gel, and ketoconazole
Lather up the scalp and leave it on for at least 10 minutes. Count on the clock or listen to about 3 songs on the radio (sing along!). Do this every night for about 2 weeks then about 2-3 times a week. If that doesn't help, you may need a prescription steroid.