General synonyms:
* Agile
* Skilled
* Proficient
* Adroit
* Expert
* Nimble
* Deft
* Cunning
* Handy
More specific synonyms:
* Ambidextrous (for using both hands equally well)
* Artful (for skillful in a deceptive way)
* Craftsmanlike (for showing skill in a craft)
* Manipulative (for skillful in handling objects or people)
* Talented (for having a natural ability)
* Masterful (for having exceptional skill)
* Virtuoso (for someone with extraordinary skill, especially in the arts)
The best synonym will depend on the specific context of your writing. For example, if you are talking about a surgeon's skill, "dexterous" might be the most appropriate word. However, if you are talking about a politician's ability to manipulate people, "manipulative" might be a better choice.