easy search results pages with custom post types

I've used CustomPress and GD CPT on various sites for setting up custom post types, taxonomies, and meta fields.

When it comes to search functionality for the front end user, I've had to create my own forms and own backend scripts to process the search query. Most of the time I use the WP_Query class to get the search results. But creating separate queries for each of my content types (because they each have different taxonomies and meta fields) can be a pain.

Since the plugin knows my content types, and what taxonomies and meta fields I use with them, it'd be nice if there was some way the plugin could also help me creating these forms and performing the search.

How do developers typically approach this? I feel like I've been overlooking something that CustomPress and GD CPT already do. Or something built into the template system of WordPress itself...

Thanks for your guidance!