You Matching parentheses is easy if you have a decent text editor.
Most editors have a feature for matching parentheses.
Learn to use it. It's usually easy to get the opening parentheses right, and then if you're in doubt, use the editor to make sure you get the closing parentheses in the right place. Some editors, like Emacs, have special modes for editing Lisp and Scheme. This feature can be helpful, but just helping match parentheses is the crucial thing for an editor for Scheme. You use the Emacs Lisp package cmuscheme.el , and it gives you a handy Scheme editing mode.