It is mentioned in the Royal Chemistry Society link [1] not to use pre-boiled water, since it has been degassed and will taste ‘flat’. This is true in my experience. I also tend to shake the tea vigorously if making it in a thermos to introduce some enlivening aeration. Admittedly, I only bother with these embellishments if making tea for others.
[1] https://web.archive.org/web/20140811033029/http://www.rsc.or...