Start with the cleanest original
Use the original camera or scan file, not a screenshot sent through several chat apps. Every save can remove detail. For a photo, use even lighting and a simple background. For a signature, use dark ink and white paper.
Crop before compression
Unused background consumes pixels and file size. Crop to the required composition while keeping the whole face, head space or signature strokes. Avoid borders and large empty margins unless the notice requests them.
Resize to the final dimensions
If the portal requests 200 × 230 pixels, a 4000-pixel camera image gains nothing by remaining huge. Resizing first reduces the amount of information that must fit inside the KB limit. Use the exact aspect ratio so the result is not stretched.
Choose a sensible format
JPG is efficient for photographs. PNG can be efficient for a simple black signature, but only use it when accepted. AavedanKit exports JPG with a white background because that is widely accepted for form images.
Check readability at normal size
Zooming to 800% makes every JPG look imperfect. First check the image at its actual display size. The eyes, face outline and signature strokes should remain recognisable. Then check the file size in Properties.
If the target cannot look good
Return to the original and improve the crop or lighting. A noisy dark photo is hard to compress. Do not repeatedly compress the same output. If the notice permits a range of dimensions, choose a smaller valid size. If the portal itself changes the image after upload, inspect its preview before final submission.