How can write an essay about cell phones?
First, choose an actual essay question. For example, you may choose to discuss both the advantages and the disadvantages of cell phones (suitable for descriptive essays) or take a position and argue that cell phones are a bliss/a curse (suitable for an argumentative essay).
Therefore, you start with an introduction finishing with a corresponding thesis statement:
E.g. The use of cell phones has a number of advantages and disadvantages
Current overreliance and dependence on cellphones makes people dumper, more distracted and less interested in face-to-face interactions.
Therefore, develop your points in the body paragraphs and summarize them in the conclusion.