Having never dealt with recruitment consultants before is it best always to phone after sending your CV through? Is there any advice for how to make best use of recruitment firms?

Depends what level you are. If you replied to an advertisement then I wouldn't bother phoning. 3 things can happen.1. You get a call back because you're suitable.2. Your CV doesn't represent you properly, so you need to write a better CV.3. You're suitable for the role but the recruiter hasn't called you back. Not the kind of recruiter you want to be dealing with.If you have sent a CV to a recruiter who has been referred to you, then yes, give them a call.