You want to catch the hiring manager’s attention with a well written personal message. Make yourself stand out. State clearly why you are messaging. For example, “I just applied to (job title) and I am eager to draw your attention to my resume”. Then tell them 2-3 relevant reasons why you are the best candidate for the position, paying attention to the language and the desired requirements listed in the job description. Finally, let them know what it is about their company that makes you so keen to work for them. Employers like to see enthusiasm and passion.