Mine turned out bland too, I think I didn`t add enough salt for a start, sometimes it`s Really something that simple that can make or break a nice meal.
when you say "jazz it up" do you mean HOT/Spicey or just taste?
for hot. you may try Mustard powder in the mix, chili peppers (rather than powder).
for Flave there`s a million and 1 things, Funugreek leaves, corinader, cummin, smoked paprica, cellery seeds, alllspice etc...
as I said, mine was bland too, but it was my 1`st ever try, and so next time I have an idea of what to adjust and get it right for our taste-buds (or lack of) :)
just don`t give up, keep trying!
So long and Thanks for all the Fish ;)