The sizes that matter
Two formats cover most needs. The in-post featured header: wide 16:9 or 2:1, generated to match your article's actual concept rather than a vague theme. And the Open Graph card at 1200×630 — the image that renders when your link is shared on social and in chat apps. The OG card deserves separate attention: bold, simple, readable at feed size, because it functions as an ad for the click. Generating it distinctly from the header, rather than letting platforms auto-crop, noticeably lifts share appearance.
One style per content pillar
The trick that makes a blog look like a publication: assign each content pillar a fixed illustration style and stick to it. Tutorials get clean flat illustrations in your brand palette; opinion pieces get moody editorial imagery; case studies get photoreal scenes. Encode each style as a reusable prompt suffix — "modern flat illustration, two-tone palette, generous negative space" — and every new post slots into a coherent visual system. flux-schnell keeps the per-post cost trivial.
Images are an SEO surface
Original images can earn image-search traffic that stock literally cannot — search engines have indexed those stock photos thousands of times and have no reason to rank your copy of one. Give generated images descriptive filenames and genuinely descriptive alt text (for accessibility first, ranking second), compress before upload so Core Web Vitals don't suffer, and reuse strong visuals across the article and its social cards for a consistent search presence.