General:
* Skill
* Art
* Trade
* Profession
* Expertise
* Technique
* Mastery
* Adeptness
* Ability
* Handicraft
For making things:
* Manufacture
* Construct
* Build
* Fabricate
* Produce
* Create
* Design
* Fashion
* Form
For a boat:
* Vessel
* Ship
* Boat
* Barge
* Yacht
* Schooner
For a cunning plan:
* Scheme
* Deception
* Trickery
* Strategy
* Tactics
The best synonym will depend on the specific situation and the meaning you want to convey.