To make a great blog, or better yet how to continue with blogging (on-going) post after post is liken to a thread and with that come a yarn and perhaps if one gets good at it, this then becomes a rope; in that it is useful=purpose and meaning which leads to longevity=permanence.
It is not so much how to make a great tea blog, because there are too many out there and one cannot possibly know which source are genuine or copied etc., instead stay true to what you have stated to doing. Think of this as watching a television show, in time this become a favorite. ..rushing home to view it and taping it when missed. But once the story line does not hold true or starts to shift focus than, you, the audience might decide it is time to stop watching this program.
I must also add that I, myself am not a good blogger. I keep at this because I am not employed and I will probably stop one day.
Oh well, happy blogging to all!