To get to the next level of table tennis, say from good club player to national team level its going to be necessary to do more than just a few single ball drills with your partners.
You need to invest in and do multiball practice with a good coach who understands the technique.
When I was actively working with the Chinese coaches we did a lot of multiball mostly based around forehand attack and pivoting.
Multiball allows you to groove and streamline your technique so that you are able to maintain a high degree of form and consistency even when fatigued or nervous.
Heres some video of my teammate Nigel Webb doing multiball in China.
Nigel is now playing professionally in the Spanish leagues.