As Creatine is stored in the body, you can take it any time. While some personal trainers recommend taking it after a workout, this has no difference in uptake.
You may wish to not take it with Caffeine at the same time, as they may possibly counteract each other when taken at the same time. Taking caffeine after creatine ingestion on the other hand can be very ergogenic.
(Common phrases used by users for this page include when to take creatine, when should i take creatine, examine.com creatine caffeine, examine.com best time to take creatine, creatine ester phosphate sodium, best time to take creatine)