Effectively using multiple domain names?

Hi Guys,

I have a website selling my video production services, I am trying to build more traffic and show up more in SE's. The websites address is just the company name at .co.uk.

I have some relevant domains I picked up cheap these are along the lines of videos-for-business and so on.

What is the most effective way to use these domains.

I can simply set my hosting to Mirror my main site at the other domains, but most of what I see online says this will hurt my place on google.

Would I be better to simply forward the domains or even build a micro-site that links to my main website?

Any advice would be a big help.

Thanks