Additional ways to minimize impedance and reduce EMI in your PCB are listed below:

• Placing extra vias near all ground pins can further minimize impedance in a similar manner as described previously.
• Avoid open space with no ground pours around. Avoid big power/signal pours generally.
• Reduce PCB height as much as possible. You can do this by adjusting the center dielectric so the current between layers has less distance to travel.