DO make sure that your CV is up to date and is in a document format that anyone can open. i.e. .rtf, doc, .docx, .txt or .pdf (though this isn’t recommended as its not editable).
DO follow up. If you don’t, you could be forgotten about, or worse, you may not seem as serious about your willingness to move than someone else who took the trouble to follow up…
DO consider why you are right for the job and what you can bring to the table. If you can’t explain why you should be hired in the context of how it will benefit the employer, you won’t be hired!
DON’T include a massive cover letter. A couple of paragraphs detailing why you should be considered for this particular job is fine but the person reading your application doesn’t have the time or inclination to read through a mountain of text before even getting to your CV
DON’T pester the company with phone calls immediately after sending your application. Give them a chance to read it before following up.
DON’T apply for positions that you have no chance or getting. If you don’t have the skills, qualifications or experience that the employer is asking for, you won’t get an interview and it will damage your credibility.