Start with the subject, not the whole photograph
Choose a photo with a clear subject and enough contrast to separate it from the background. Crop around the face, pet or object you want to stitch. A small subject in a wide landscape will receive only a small fraction of the stitches. For a portrait, leave enough room for the outline of the head; cutting at the chin or ears can make the finished shape hard to read. Keep an untouched copy so you can compare each change.
Choose a stitch budget first
A 100 × 100 chart contains 10,000 grid positions. A 200 × 200 chart contains 40,000: doubling both dimensions creates four times the work if the same area is filled. On 14-count Aida those widths are about 7.1 and 14.3 inches. These are design sizes, before mounting margins. Start at a size you are willing to stitch and judge whether the important details survive; do not enlarge the chart just to keep every background detail.
Simplify the background
A busy background creates extra colors and isolated stitches. Crop it away, use the generator’s background-removal step, or choose a simpler photograph. Check fine edges after removal, especially hair and whiskers. Removing the background does not automatically make a low-resolution face sharper. If important features are lost, keep the original background and crop more tightly instead.
Compare color limits and contrast
Generate a first chart, then compare a smaller and a larger color limit at the same stitch dimensions. Look at eyes, shadows and the outline of the subject. A smaller palette can simplify stitching but may flatten subtle shading. Adjust brightness and contrast gradually; clipping light or dark areas can remove information. Dithering can suggest more tones but can also create many isolated stitches. Inspect the chart close up as well as from a distance.
Check the pattern, not just the mockup
Before downloading, inspect the symbol chart and floss counts. A pleasing image can still contain scattered single stitches that are tedious to work. Compare the cleaned chart with the source and decide which small details you can lose. Save a version you like before experimenting further. Use the fabric calculator to add cloth margins, then confirm key colors against physical floss rather than a screen.