When writing effective English, I like to follow these rules:

Have a narrative

I always try to find a way to write an engaging story - whether it is for sections of an annual review, articles for a global magazine, or promos for a corporate video. Without a narrative, copy can become aimless and less appealing. A story structure - with its beginning, middle, and end - can keep readers engaged. 

Use of adjectives

Adding adjectives to copy can make an immediate impact. Adjectives make copy more emotive, attractive, and eye-catching. But it is important not to use too many. Readers/ customers can sense when they are being oversold on something, which can make the copy sound cheesy. 

Avoid over reliance on conjunctive adverbs

I find that using too many of these adverbs (furthermore, consequently, however, etc.) can make copy read a bit like a thesis, and subsequently boring for the reader. When I purposefully try to avoid these adverbs, my writing becomes more inventive, succinct, and improved.

Short sentences

Some clients like to include achievements and mission statements within a series of long sentences crammed with facts, figures, and commas. This can make the copy read like a shopping list, and simply too long to interest the reader. Long sentences are fine, if they serve a purpose. But alternating this with shorter sentences can make more of an impact, and keep the reader interested in reading on.