You write in a dull manner by not putting enough action into your stories. Write long, boring descriptions of things and have the characters blather on and on about nothing.
boring or dull
Dull, tedious, repetitive.
An antonym for tedious (dull, repetitive, boring) could be exciting, challenging, interesting, or fascinating.
"Boring" is the most used synonym for tedious although there also is "banal"; "wearisome"; "vapid"; "exhausting"; "arid" and "dull".
uninteresting, tedious, dull, dreary, mind-numbing
boring, dim, dumb, repetitive, dreary, stupid, tiresome, or tedious. Those are all opposites of dull.
There are several words that have the same meaning and use as the word tedious. Some of these words include boring, dull, repetitive, and uneventful.
dull, boring, ordinary, plain tiresome, tedious, boring, dull, mind-numbing.
dull, boring, tedious, drab, tiresome, monotonous, humdrum, uneventful
The adjective dull has the adverb form dully. It can mean in a dull way, or sluggishly, or in an obtuse manner.
boring, tedious, dreary, flat, plain, monotonous, run-of-the-mill, humdrum
dull, boring, tedious, drab, tiresome, monotonous, humdrum, uneventful