A resume objective is crucial to the success of your entire resume. This is usually the first section a potential employer will read and so making a great first impression could be key to securing an interview and hopefully the job.
A resume objective should really sell yourself to a potential employer and so you need to make sure that you structure it in a way that it makes it sound like the job was designed for you - and no other candidate could possibly be as well suited to the role as you are.
Draw on your previous experience and qualifications in a succinct manner. Always make sure all spellings, punctuation and grammar are spot on as if you have some spelling mistakes in your resume objective there is a good chance the employer won't even bother reading the rest of your resume.
You should always learn by heart what you have put in your resume and resume objective, in case you are quizzed on a certain aspect of it while in a job interview. If you are hesitant or look surprised that you had put something in then it will look to the employer that you have made it up.