What is best way to handle complex search?

Hello,

I am currently using get method to retrieve parameters and query database.
The problem I am having is I need to preserve the current query parameters and allow user to narrow search.

Example url
http://localhost/myapp/products/show_sea...meter=None

Now the user can click on a image of products and I want to narrow the search while still using the original parameters.

New url show pick_brand filter
http://localhost/myapp/products/show_sea...meter=None

Is this the best method to search, url looks ugly.
Or should I use post and store in session variable?

How would you do it?

Thanks