Towards more picturesque speech™
- “Practicable” means feasible: able to be done or successfully put into practice: “I planned to build and operate a working model of the Chrysler Building out of cream cheese but the machine-age gargoyles wouldn't keep their shape and the needle kept drooping. I concluded it just wasn't practicable.”
- “Practical” means useful: “the door to the hen-house came of its hinges but, fortunately, Our Bill is quite practical: he jury-rigged some chicken wire and an electromagnet, and the chooks don’t go near it now”.
In a legal document, one generally means “practicable”, and will see it in tiring and emotive phrases like “all reasonably practicable steps” and “as soon as reasonably practicable”. Of course you could always use “feasible”, but that would spoil the fun pedants have in pointing out when you have confused “practical” and “practicable”, wouldn’t it.