For the first 3-5 days, use the account like a real person: complete the profile, add a photo and bio, scroll for 10-20 minutes a day, watch videos through, like, save, and leave thoughtful comments in your niche.
Avoid posting during that first window. After warmup, start with 1-2 posts a day and keep engaging daily. This gives the account human behavior signals and helps the algorithm understand your niche.