honestly a good support is in the player you have to understand the champion you choose for instance if you choose leona you have to be aggresive and go in and kick some balls and take a few hits for your adc but its okay its what your champ was made for you q litteraly sends you diving into the enemy
One of my close friends mains Leona support, and it can end up destroying the enemy team's morale if he has a good game. I play a variety of supports every now and then, but I've always been fond of playing Sona support for the large amounts of utility she brings to a team comp. Also, DJ Sona best Sona.