We first developed this bootsrap theme editor for our own purpose to create theme a lot faster. Here are some technics to become a bootstrap theme chef with this tool.
You don't have to type out variables and Less functions every time. Defined variables (starting with @) and Less functions (like darken(@color,10%)) will automatically appear in a list as you start typing. Prediction + autocomplete = awesome typeahead
Change a variable and you can see the result immediately. No scrolling to check the impact of what you changed.
If you already have variables defined, you can import them right into boostrap-magic.
The colorpicker tool lets you easily see and choose colors so you can find just the right ones for your theme.