If you want to write good academic essays (that'll score at least 6.5 in IELTS), then you must practise using the four paragraph structure and you must develop the habit of writing TOPIC SENTENCES. Some of you may not know what a 'topic sentence' is. A topic sentence:
is an introduction to your paragraph
is usually the first sentence in a paragraph
tells the reader WHAT the paragraph is about
connects the paragraph to the essay topic or statement
is not too BROAD (= too general) or too NARROW (= too specific).
The ways in which people travel has changed considerably over the past few decades. Not only have vehicles become more comfortable and affordable, but roads and highways have become safer and more well-designed. More places are now connected, by land, air and sea.
Do not disregard this step. It is important. To write effective essays you need to get into the habit of writing topic sentences. 'To get into the habit' means to do something many times so that it become a (good) habit for you.
For more information, watch the short video that explains how topic sentences are like maps - they help the reader know about your essay.