Rewrite rule for custom page content

Hi,

How do I create SEO friendly safe URL's using my htaccess?

I am using "Perch" where I have created my own custom content template for "Products" which are also categorized using a select drop down, this all works well but how do we change the URL to a SEO friendly safe URL "/products?cat=kitchen&s=product-one" in my htaccess?

Regards Craig