Focus on expression first
Emoji-style stickers are small and emotional. Use photos where the eyes, mouth, and head angle are clear enough to become a readable reaction.
Create a set of moods
One custom emoji is fun, but a set is more useful. Try happy, crying, shocked, angry, confused, sleepy, love, and laughing as a starting pack.
Avoid over-detailing
Tiny accessories, busy backgrounds, and long text can make custom emoji hard to read. Strong shapes and simple captions usually work better.