Okay...this is what works for me, I follow the KISS process on this and I enjoy it.
My family drinks homemade sweet tea, typically two or three family size Lipton tea bags per gallon plus one cup of sugar. I use that once freshly made. Always using 2-4 oz of last batch plain kombucha as part of the starter. If you have no starter, add 1 tbsp distilled must be pasteurized vinegar per quart. But one of my favorites are two green jasmine plus one orange pekoe, individual size, steeped while covered for ten minutes, one quart of water, 1/4 cup sugar. Ferment on counter, wrapped in dark towel for five days at 68-70F. Strain, add flavor component which is usually a shot of fruit juice per 16 oz PET bottle, tightly capped, back on counter for 24hr and then to refrig. Continues a slow ferment in refrig and bottle carb. No pH checks for me. I only make one quart per week because I also consume water and milk kefir...but I find during cool weather I consume more kombucha so I double production.
There are going to be varied techniques, you work with what tastes right for you.
Motto: quel che sara sara