You can keep a consistent person, face, or subject across images in a few ways:
Style Reference in Venice Studio (recommended): upload a reference image at venice.ai/studio/enhance and generate new images guided by it.
Seed values in Classic Chat:
Write a detailed prompt describing the subject.
Generate your image.
When you find one you like, open Image Details.
Copy the seed value.
Enter that seed in your image settings.
Adjust the prompt while keeping the same seed to create variations of the same subject.
Image editing: modify an existing image while keeping the same subject.