General synonyms:
* Custom-made
* Tailor-made
* Made-to-order
* Personalized
* Customized
* Handcrafted
* Individually designed
* One-of-a-kind
More formal synonyms:
* Commissioed
* Hand-fashioned
* Specially crafted
Informal synonyms:
* Custom
* Special order
The best synonym to use will depend on the specific context of your sentence. For example, "custom-made" might be a good choice for describing a piece of clothing, while "commissioned" might be better suited for describing a piece of artwork.