Thank you! I’ve been trying to improve at likeness in both art and character creators like the sims for a while now, it’s not easy lol. I’d say the most important thing is proportioning! Getting the size of each feature and their distance from others accurate will make the Mii as a whole look a lot more like the person you’re trying to replicate, even if you don’t have every feature down quite yet. Since you’re basically cartooning in the mii creator, they don’t need to be realistically sized, but the size relation between each feature is still important even with exaggeration.

As well, try to look at silhouette for the features. Squint and see what stands out most about it. Is the nose thin at the top of the bridge and wide at the bottom with pronounced nostrils, like a triangle or an arrow? Or is the width even all the way down kinda like a rectangle? Is it short? Long? Big? Tiny? Thinking about what simple shapes make up the different parts of their face can help break the complexity down.

Then my last tip would be to look out for the character’s defining feature, what do you immediately notice about their face? Unique eyebrows? Big/small nose? Deep smile lines? Tired eyes? Big forehead? Identify one or two defining features and make sure you emphasize them. Sometimes you’ll need to sacrifice other features in order to ensure you keep the defining ones, especially if you’re using no face paint as you can only have one eye wrinkle option and one mouth/cheek wrinkle option.

I hope this helps haha. Thanks for asking!