In a half gallon jar, put your tea bags and sugar.
If your tap water isnt safe, you'll need to boil whatever drinking water you use, otherwise make sure your tap water is running hot (rinse some dishes while it runs to not waste water!) and then fill your jar half way full. My tap water runs about 115F.
Stir to dissolve the sugar, Let it sit for at least ten minutes, but its okay if you forget and it sits longer.
Take the tea bags out, pour ½ cup of plain kombucha (most likely saved from your last batch) into the jar, fill up to about 2 inches from the rim with cold water, then plunk in your scoby.
Put either a coffee filter with elastic or metal canning ring as lid, or a piece of cloth with ring or elastic, or even just a plastic lid screwed on loosely to allow air to escape. It already contains all the good bacterias it needs to brew, you're just protecting it from bugs getting in.
Depending on your indoor temps, it could take 5 days, it could take 10 days for your kombucha to be ready. I suggest after 3-4 days if your house is hot, (above 25C/80F) 5-7 days if your house is cooler, you simple taste the kombucha. I literally just take a swig from the jar, but you can pour some into a glass or pop a straw in there. If its still too sweet, leave it another day or two. If it tastes right, its time to secondary ferment!