Dripping can take a little trial and error, all attys are'nt alike. Some will take 3 drops and some will take 4, and others more before they are flooded and leak.
I'm no dripping expert, but I find I usually have to prime them before they start working well, basically I flood them at the start intentionally, put way more liquid in than I know it actually takes, to get everything saturated. Then I'll blow them out and leave the remaining excess juice leak onto a paper towel or something, after that I start vaping till the flavor starts to dissipate then add 3 drops. If that works well i'll add 4 the next time, and so on till I know how much I can add before it leaks. I'm sure others do different, but that's what works for me. Cleaning them before starting, like mentioned before, is also good advice.