As often as possible! That’s different for everyone. Shoot multiple times a week throughout the year if you can. When practicing be sure to practice real-life hunting situations and not just perfect broadside shots while standing comfortable at known distances.
Shoot at different angles, shoot out of your stand, shoot after doing sprints so get your heartbeat up, shoot at low light. Shoot as many different scenarios as possible so when you get that once in a lifetime opportunity, you have practiced some version of it before.
Remember to keep practice fun, the more fun it is, the more often you will do, and ultimately enjoyment is the reason we bow hunt in the first place.