Crop to the subject
This is the biggest fix. A face or object that fills the frame has room to survive at a low resolution; a small subject in a busy scene turns to mush. Crop before you upload.
Raise contrast and saturation
Dull phone photos pixelate muddy. Nudging contrast and saturation up separates the shapes and gives punchier, cleaner colors. A little goes a long way — push until the subject pops, not until it looks fake.
Tip Boost contrast first; it does more for clarity than any other single adjustment.
Keep dithering on
For photos, leave dithering on. It blends colors to keep skies, skin, and shadows smooth instead of banding into hard stripes. Turn it off only if you want a deliberately flat, poster-like result.
Find the right color count
Too few colors and skin tones go blotchy; too many and it stops looking like pixel art. For photos, 16–32 colors is usually the sweet spot. Start at 24 and adjust from there.
Do not over-shrink
A tiny grid destroys facial detail. For portraits, keep the pixel size high enough that the face stays recognizable — around 96–128 — then lower it only if you want a bolder look.