I use gulp and find it really simple but also powerful and customisable.

I did a quick google and found this tutorial which seems to look like it has lots of great tutorials.

Theres also assertic which does a similar job using php. I've never used it but it seems to be quite thorough and it would be easier to integrate with laravel and a build process with laravel commands.

The third is codeKit for OSX. Its a nice gui asset compiler. Make sure you comment with what you finally go with. I'm curious.

Read this tutorial http://www.techigniter.in/tutorials/minify-and-combine-css-and-js-using-laravel-elixir/

This part of the Laravel documentation gives you all you want : http://laravel.com/docs/5.0/elixir

i find a free online service to minify js http://www.online-code.net/minify-js.html and compress css http://www.online-code.net/minify-css.html, so it will reduce the size of web page.