How to serve a heavy backspin serve

I want to learn to serve a heavy backspin serve that is Very similar to this jun mizutani serves here: https://www.youtube.com/watch?v=1hDu0hidsX4 ,One that will somewhat travel back in the direction of the server.

Currently when i serve backspin i contact/brush the ball at the backside (i will brush the ball down the backside 4 o'clock position). The speed of the ball and forward momentum is fine, and i can also get it to travel very low over the net, the issue is that i feel there is not enough backspin.

Then My friend told me to brush underneath the ball (I assume directly underneath, at the 6 o'clock position), but when i try to do this way, i will get a lot more backspin, however upon contacting the ball, the ball will travel UP HIGH and with little forward momentum - the ball feels like it has lots of upwards momentum and too slow.

However, just like the mizutani example, how can improve my serve to get the ball to have lots of backspin, but still keep it low and fast?

Thanks

Hi Aaron,

Take a look at this video, Mizutani High Toss Service. Also take a look at this one on the Ma Lin Serve  which will also help.