In academic English, short sentences and paragraphs are often clearer, more readable and more effective than long ones.
Read your work aloud to make sure you're not rambling.
Read your text aloud to check that it flows well.
It is vital to get quality feedback on your manuscript by approaching the right person for each aspect of your writing: an expert on the subject to check the content; your supervisor or a colleague to check the argument; a trusted friend with good writing skills to check the grammar and punctuation.
It is helpful to get a colleague or fellow student to read through the work to see if the argument is clear.
Always set aside your writing for at least 24 hours and come back to look at it with fresh eyes.
If a paragraph refuses to flow, underline the essential parts that must be included, work out the best order and add only enough words for the paragraph to make sense.
It's hard to analyse your own writing but there's a simple, straightforward way to check how your writing will come across.
Don't be scared of the delete button - it can be your most valuable tool for sharpening your writing.