6 ideas
The decline of language has political and economic causes, but its effects become causes in turn: foolish thoughts produce slovenly language, and slovenly language makes foolish thoughts easier to have. Like a man who drinks because he feels a failure and fails more because he drinks, the cycle is reversible only by deliberately breaking bad verbal habits.
Stock phrases and dying metaphors arrive ready-made, like prefabricated hen-house sections, so the writer assembles sentences instead of choosing words for meaning. Each ready-made phrase anaesthetizes part of the brain, and the phrases will construct your sentences and partly think your thoughts for you, even concealing meaning from yourself.
Political speech is largely the defence of the indefensible, so it must use euphemism, question-begging and cloudy vagueness. Bombing villages becomes 'pacification' and forced expulsion becomes 'transfer of population', names that let people discuss atrocities without calling up any mental picture of them.
When a gap opens between a speaker's real aims and declared aims, they instinctively turn to long words and exhausted idioms, like a cuttlefish squirting ink. Read inflated or abstract prose as a symptom and ask what concrete meaning the writer might be avoiding.
Never use a metaphor, simile or figure of speech you are used to seeing in print; never use a long word where a short one will do; cut any word that can be cut; never use the passive where you can use the active. Never use a foreign phrase, scientific word or jargon if an everyday English equivalent exists. Break any of these rules sooner than say anything outright barbarous.
For every sentence, ask: What am I trying to say? What words will express it? What image or idiom will make it clearer? Is this image fresh enough to have an effect? Then ask two more: Could I put it more shortly? Have I said anything that is avoidably ugly? This lets meaning choose the words instead of letting words choose the meaning.