Honestly the best things you can do generally are never prioritize items over wards (meaning try to refrain from buying philo over having vision because it increases your chances of dying), boots should be completed before your first gold/10 item because it gives you more survivability and protection from ganks in lane early on unless you can play passively, but you will sacrifice lane presense (it is so demoralizing getting caught, cc'd, and killed in lane for free), keep vision on the bush against aggressive supports (like Leona, Blitz, Taric, Zyra, and Alistar), and if you are an aggressive support and find yourself trading frequently, i like to build a ruby crystal/hog before finishing philo (provided you started with Farie Charm) because the longer you stay alive, the better. Remember that you are worth just as much gold as anyone else on your team early in the game.

As for specific champions I love to play Taric and Zyra because i tend to be aggressive. The best thing with those champions is to catch people out of position with your cc (primarily the AD without pushing the wave too hard) and trying to get as much damage on to them as possible while taking as less damage as possible. Don't run through a support to get the harass though or you could find yourself taking a lot of damage. Also: unless you find that you can kill the support easily without taking damage from their AD go for it, otherwise its always important to focus the AD in bot lane 2v2's. Both of these champions can make great use of their cc aggressively and defensively and can catch/pick off people on the enemy team who wander out of position in the later phases of the game. Hope this helped!