I'd say in addition to shell, editor, compiler, one should also have a version-control system handy. After manually working through a handful of simple example

I'd say in addition to shell, editor, compiler, one should also have a version-control system handy. After manually working through a handful of simple examples, a more complex undertaking will be very nonlinear; what better way to reinforce the learning than to keep track of the enhancements, improvements and fixes, and reasons for each change? This falls into the same category as copying examples by hand: being very deliberate, thinking through and providing rationale for each change you make.