Get to the point.
Get your main message across quickly so your reader knows what you are trying to tell them.
What is wrong with this sentence?
In an effort to curb the movements of refugees, which followed Ankara saying last week that it would no longer stop refugees trying to enter Western Europe from Turkey after the death of scores of its soldiers in airstrikes in Syria, Athens suspended its asylum procedures.
The reader has to get to the end to find out what the sentence is about.
The main point is in the final phrase: Athens suspended its asylum procedures.
But many readers may never make it that far. If they have to work too hard to grasp your meaning they may give up before they reach the end of the sentence.
We can make the sentence more effective by rewriting it this way:
Athens suspended its asylum procedures in a bid to curb the movements of refuges. Many more people began moving to the border last week when Ankara said it would no longer stop refugees trying to enter Western Europe from Turkey after the death of scores of its soldiers in airstrikes in Syria.
That still leaves us with quite a long second sentence, so here’s another piece of advice:
Stick to one idea per sentence.
If you cram too many ideas in your reader may find it difficult to grasp your meaning.
So let’s try a simple fix and break the second sentence up.
Athens suspended its asylum procedures in a bid to curb the movements of refugees. Many more people began moving to the Greek border last week when Ankara said it would no longer stop refugees trying to enter Western Europe from Turkey. It was reacting to the death of scores of its soldiers in airstrikes in Syria.
Now we have three clear sentences replacing one confusing sentence. So I’ll leave you with one more piece of advice.
Ask yourself: Is this sentence too long? Can I break it up so that each idea has more impact?