Batching

Batch as much as possible operations that rely on the same state, because changing the system state (by using the glEnable() and glDisable() calls) is costly. OpenGL does not check internally to see whether a specific feature is already in the state you want. In the exercises in this book, I would frequently set states more often than I likely needed to, so as to ensure the behavior is easily predictable. But for commercial, performance-intensive apps, try to remove any redundant calls in the release build.

Also, batch your drawing calls as much as possible.