After a philo, you probably want to rush a sightstone, maybe even a ruby sightstone. Once you have that, you'll still want pinks and even regular wards for places where you want permanent sight (dragon, tri bush if you're purple side, etc) and then just use sightstone wards for immediate sight. That way, you don't place a sightstone ward and accidentally get rid of an important ward.
My Superheroes consist of the band members of the Who, Led Zeppelin, and The Beatles
I start faerie. 3 wards, 2 health pots. I grab Philo Stone and 2-3 wards on the first back to start the gp/10 asap, then next back is Sight Stone. After getting the Sight Stone I stop buying green wards on each back and get pink instead. From there I've got Philo and SStone, so next I get boots and 1-2 pink wards, then Ruby Sightstone, then whatever support items I feel I need. Regardless of who I play as support my first items are always philo > SStone > boots > RSStone, not buying pink wards until I get the first Sight Stone. I like to rush the Ruby Sightstone because the early health is helpful in lane, and that with pink wards lets me keep every possible gank route warded, dragon pink warded, and I have an extra to ward the enemy buff.
I probably buy 4-8 green wards and 10-30 pink wards per game.
I'm a little cheap when it comes to wards early game, but I do rush a SIght Stone after Philo and get the Ruby Stone after boots. I start off with fairie charm, 3 wards, and a mana and health pot. I usually have the mana biscuit and the 1 minute ward from the utility tree so that helps.
Rush Sightstone if you can. Generally, you only need to buy 1 ward every time you back, 2 if your opponent has brush control. Later on, if you have a SIghtstone upgraded, all you need really is either a Pink Ward every time you go to shop, or refresh your Oracles when it's down.