I have tried several over-the-counter insoles and the one I prefer is made by Superfeet. What I like about Superfeet is that they are lightweight, thin, durable, and have a decent heel cup. This last feature is important because the two most common reasons for overpronation are collapsing of the arch and turning out of the heel. If you know your feet overpronate, a good insole might give them the support they need to reduce the risk of injury.
They are more expensive than those you’ll find at the local convenience store, but the quality is well worth it. They even make a special insole for high heels.
If you have an injury you should first consult your physician or physical therapist to determine if this type of insole is appropriate for you.