as salam alaikum
during your salat remind yourself that you are in presence of the Almighty and that you are fulfilling His order and answering His call. You are in the most beautiful moment between you and Him. Then make the movement of your body follow your heart while praying and continue to remember Him. If we are immersed in the remembrance of Allah, Shaytan finds no way to us but if we are negligent he sneaks in and find a way to influence us. If you can, pray your supererogatory prayers with love and not by forcing yourself doing them, and talk to Him before and after prayer.
With prayers for your success.