To create and optimize your programmatic advertising campaigns, you need to follow some best practices. First, you need to define your objectives, budget, and key performance indicators (KPIs) for your campaign. Second, you need to choose the right platforms, channels, and formats for your ads. You can use display, video, native, or social ads to reach your niche influencers. Third, you need to design your creative assets and copy that match your niche influencers' style, tone, and preferences. You can use tools like Canva, Adobe Spark, or Lumen5 to create eye-catching and engaging ads. Fourth, you need to set up your targeting and bidding strategies based on your niche influencers' data and audience segments. You can use tools like Google Ads, Facebook Ads Manager, or MediaMath to manage your programmatic advertising campaigns. Fifth, you need to monitor and optimize your campaigns based on your KPIs, feedback, and results. You can use tools like Google Analytics, Facebook Insights, or Moat to track and measure your campaign performance.