I would recommend CC. Crowd Control is the best way in my opinion that you have a higher chance at winning teamfights. Some solid examples in my opinion is Amumu-s AoE stun, Sejuani's whole kit, Hecarim ultimate, etc. One or two of these can make your team a threat.
Aside from that, you need an AD carry that works well with the rest of the team, but that can also handle early game well enough to make it to the teamfights. I particularly like sivir, vayne, or tristana, and lucian as well.
Midlane you need a burst champion. This lane usually levels to 6 first, and can commonly be the focus of ganks, or be the lane with the most minions. This means that this champ has an advantage in lane, because he can bring his/her more advanced stats and kit to any lane of their choosing. I enjoy picking someone here who has a solid kit that corresponds well with the team. For example, if you have an Amumu jungle, I enjoy morgana. flash to the center, pop your ulti right after amumu's, and enjoy the eternal stun.
Top lane, I prefer having a tank or a tank-buster. Someone like riven is good in top lane, but if your team is too squishy riven will merely be another easy kill. If you have diana jungle, nami supp, sivir adc, and xerath mid, you will have to pick someone tanky with CC. In this type of comp, I enjoy gnar. If you have a tanky supp and jungle, Jax-type champions are good. AoE stun, immense damage, good chasing, multi-build potential, and adds heavy damage that allows for a target.
Your support must correspond not only to your adc, but to your team. If you have a heavy engage team, Janna might be a good option for disengage. If you need tank, braum or leona are solid options. Supports often forget that they can roam, once bot is out of danger. Alistar is a solid roamer, with the potential to just destroy the midlaner out of nowhere, while providing heavy tank.
You need to take into account other factors too. How well does this champion scale, where are their power spikes, where will mine be, is there CC/éngage/disengage... So when you pick in solo queue, try to master a few good champions. In my opinion, you can never have too much cc, because cc can dis- or engage.
Any team comp works well though imo. It's more if you're in sync with your team that counts. LCS people pick lulu mid, but not for burst, but more to buff up their main damage dealer, etc. Pick a tactic you feel is needed, and try.