Playing Support is a bit more complex than simply picking a champion that brings enough utility that not being able to farm isn't a problem. Unlike other roles, you would interact with one ally significantly more than the rest, because of this, picking a support that compliments your carry's strengths or shores up their weaknesses can make all the difference. That being said, the game is still 5v5 and synergizing with the rest of your team as a whole may end up playing a bigger factor (especially if you find your carry companion to be...a bit lackluster). Depending on your team's strengths or enemy's weaknesses, you want to try and figure out whether you want to help your team engage fights, peel away enemy engages to protect your carries, or have the flexibility to do both. Generally, supports that are able to fill both roles are best for blind picking, but supports dedicated to either engage or peel tend to perform those jobs better.

Engage- Leona, Alistar, Annie, Blitzcrank, Taric

Leona and Alistar are the epitome of engage supports - once they've found a target, they can stun lock that target for easy kills all the while being obnoxiously tanky. Alistar has a bit more breathing room and flexibility due to his heal and standalone knockup, but a Leona only has one choice - get as aggressive as humanly possible. Taric is the most unique engage support in that he provides a static aura that benefits the most on a frontline, but has heals and damage increase auras that would best help a backline. That being said, Taric does little to acually peel for his carry, so his utility is still best catered to offensive plays. Annie and Blitzcrank bring a safety measure in their initiation, and so, can be used to peel for their carries in emergency situations. The downside of this seemingly good characteristic is that both champions are heavily reliant on landing their signature abilities in a pinch and missing too many skillshots can result in catastrophic results for your team.

Engage supports will best compliment marksmen that can burst targets that are locked down and survive teamfights with their own escapes. Graves, Lucian, Corki, Quinn and Caitlyn are arguably the best marksmen that fit this category and lane combinations with the likes of these champions coupled with the supports listed above have a great chance at winning the laning phase.

Peel- Soraka, Janna, Lulu, Karma, Bard, Zilean

Peel supports are great 'Get Out of Jail Free' cards for mispositioning carries and bring a lot of harass potential with them to lane. While most peel oriented supports lack hard crowd control abilities to lockdown targets, they make up for this apparent weakness by emphasizing movement speed and can quickly change the tide of most chases one way or another. Janna, Lulu, Karma and Zilean all best showcase these traits - they all have massive movement speed steroids and will win extended fights after poking enemies down, but can be quickly shutdown by burst oriented champions. Soraka and Bard, on the other hand, rely on their carry a bit more than most supports. For Soraka, the carry can be a bit reckless and still be fine due to Soraka's heals, but Soraka can't heal herself, and so has to rely on the carry doing the brunt of the work. By contrast, Bard is dependent on a carry that can safely handle farming in 1v2 scenarios (with a handful of health packs to fall back on) for short bursts of time, as Bard is dependent on collecting a lot of chimes scattered across the map.

Peel supports will best compliment marksmen that rely on late game scaling and are susceptible to being shut down with quick bursts of damage. Vayne, Kalista, Kog' Maw, Ashe and Jinx players will benefit the most from avoiding fights in the early game and focusing their efforts on gaining small advantages in lane instead.

Bit of Both - Morgana, Braum, Thresh, Zyra, Sona, Nami

Braum brings a suprising amount of versatility to his team - offering a way to block projectiles, stun every member of the team indivually in a single fight, quickly reposition to friendlies and knockup the entire enemy team, effectively disrupting any engage or retreat. The mustachioed strongman can singlehandedly throw a wrench into an enemy composition that relies on long-range engage abilities like Morgana's Dark Binding, Ahri's Charm or Ashe's Enchanted Crystal Arrow. Thresh still reigns supreme in overall versatility, largely due to the fact that he provides a great repositioning tool in his lantern, all while being able to lock down targets and slow overly aggresive targets down. While a great deal of Thresh's strengths come from all the different ways we can help his team out simultaneously, Thresh's Dark Passage is a particularly invaluable tool for carries that lack inherent escapes, like Varus or Miss Fortune. Morgana and Zyra are supports that are best used for peeling, but have enough crowd control that locking down priority targets can also be done in a pinch. Sona and Nami have similar styles of play, but emphasize repairing damage through heals rather than preventing damage by shielding and/or bursting down targets.

Champions that can both peel and engage are great picks to default to, because they're almost impossible to completely shut down. Due to their high safety margin, however, champions with a lot of versatility will often suffer from the 'jack of all trades, master of none' syndrome and will never be able to go toe to toe with a support with dedicated traits. These 'balanced supports' will compliment equally versatile carries that have strong laning presence but shine most in mid game teamfights, such as Ezreal, Tristana, Draven and Sivir.