One of the easiest ways to make writing look better is to use synonyms.

Avoid ‘kindergarten words’

In western schools one of the first things writing teachers teach is to avoid ‘kindergarten’ words.

An example of these words:

Adjectives

good: positive, grand, excellent, wonderful
bad: atrocious, dire, pitiful
big: vast, enormous, giant, great
small: minute, tiny, miniscule
clever: intelligent, wise, genius, knowledgeable
stupid: idiotic, moronic, poorly devised

Verbs

go: head, visit, frequent
say: declare, announce
do: act, perform
have: own, possess
build: construct, erect, develop

Nouns

work: employment, labour, job, career
car: vehicle
music: tune, piece, melody

More synonyms

An in-depth list of synonyms can be found here.