[Rav Yisroel Belsky][1] ([zt"l][2]) [said][3] that one should lean slightly to the left, with one's elbow on the table, in a very comfortable manner. See [the YouTube video][4] for more detail.

Here's a screenshot from the full clip:

[![Rav Yisroel Belsky sitting at a table, leaning slightly to his left with his left elbow on the table, and holding a styrofoam cup in his right hand.][5]][6]

(*Click the image for a higher resolution copy*)

  [1]: https://en.wikipedia.org/wiki/Yisroel_Belsky
  [2]: https://en.wikipedia.org/wiki/Honorifics_for_the_dead_in_Judaism
  [3]: https://judaism.stackexchange.com/a/81082/5323
  [4]: https://www.youtube.com/watch?v=ssZY25Fj8qE
  [5]: https://i.stack.imgur.com/zWrRPm.png
  [6]: https://i.stack.imgur.com/zWrRP.png