Recently I changed my workflow, using some of the best tools available: gulp.js, gulp-sass and Browser-Sync.
I now work faster and better when creating responsive websites.
Using gulp.js I no longer need to combine, compress or process my SASS by hand, it is all done by gulp’s streaming build system.
Add Browser-Sync and you truly get some amazing power! Any changes in my SASS/CSS is displayed instantly in my browser without refeshing. Connect as many devices as you want to the URL generated by Browser-Sync and the project will be displayed and refreshed on these devices instanly as well.
gulp.js, gulp-sass and Browser-Sync allow you to setup your own device lab for responsive web design.