Okay since playing cait I noticed personally going with 2 doran's blades from the get go seems to be of less value then 2 daggers. As well the 2 daggers will build into a phantom dancer later. I also use teleport instead of flash for a quick port back into a lane and ghost to catch up in the beginning to an enemy or run away. I also find laning in top or bottom lanes are more effecient if possible for ally support and more enemies to kill. I tend to use traps quite a bit either near my turret for defense or near the enemies turret when they are trying to defend, I also toss them out near bushes or in bushes.

Doran's Blade >> 2 daggers >> boots of speed >> either vampiric Scepter or boots of swiftness but get both >>> change vampiric Scepter into the bloodthirster >> then turn the 2 dagger into phantom dancer >> the bloodthirster or infinity edge whichever you prefer to get first then the other. If needed you can always switch some up with things such as madred's bloodrazor for tanky types, the black cleaver, sword of the occult, or etc.