Here's a great tool that lets you plan out your Tomodachi Life island layout: https://www.youtube.com/watch?v=e07ettFz7PI

The fashionista quirk gives your Miis the ability to swap between clothes you give them on their own, which I really enjoy.

I pet my fav mii's head like 20 times a day because I love him so much he's so cute. It's not for his happiness anymore it's for mine

If a mii is in a bad mood, if you bring a different mii to them you could get different cutscenes!

You can tuck in a Mii`s shirt by pressing down the left analog stick when dressing them.

So one hack I kinda found was from my island negligence. One of my mii's complained the island was lacking in pathways and amenities, so when we added them, they added benches, bonfires, sprinklers and 3 soda machines all for about $30 when it should have costed over $400. So probably minimal design until someone complains might be a good way of getting certain quick build items without having to pay a fortune. The obvious downside is the items in question you get are random

16:49 found that sending a sad Mii on a holiday is another good way to cheer them up. Give them a change of scenery to make them feel better

I notice that the quirky/ normal meter is that my quirky characters are often turning on an off lightswitches, following others, playing on things. Where the normal miis just walk around, sit on a bench and things like that

They should add a whole playground with several things for miis to do! Like swings, a slide, a jungle gym. It would be a great place for them to hang out

I set miis to be father and son irl and when they finally moved in together there was a news segment saying something like “turns out they’re father and son” and it changed their relationship to parent and kid like when miis have kids

A few other tips:

To completely flip someone from sad to happy, give them a wish vacation ticket. Kermit the Frog got rejected by Hatsune Miiku today and sending him into space cheered him right up.

A weird thing is that if you have two miis related to each other in setup, that seems to only show up after they move in together

Localization has big differences. In the UK version the drawing mode has "alpha lock" but in the US version it's Transparency Lock.

You can use that feature to add shading. If you need that part in the middle of your drawing, do that bit first then save it as a sticker. Do the other layers as needed, then stack them in the end.

With the face paint tips, just some clarification.  Alpha/opacity lock (name changes in English based on region) doesn't lock you to drawing on the face, it prevents you from drawing where you haven't drawn already -- locking the opacity in place, hence the name.  It's specifically for when you want to add details to paint you've already placed down, without going past the edges.  Because of that, it's a godsend for shading.

If you want to add a shading gradient to a part, always toggle the opacity lock, and then either use a brush with a color for cel shading, OR toggle on the darken/brighten/layer options to create a smoother gradient.  What those three do is pretty self-explanatory but:
Darken: Makes whatever you draw over get darker, towards the darkness of the color you're using.
Brighten: opposite of darken, brings the parts you draw over to the brightness of the color you chose
Layered: Brings whatever you draw over closer to the color you chose, not just the brightness level.

All three add transparency to the brush, so you can do multiple runs over parts to create smooth gradients.  Very, very useful.  And with the opacity lock, you're not going to be drawing over the areas you want kept blank.

One thing I wish I knew sooner is the fact that you have limit of objects you can place on your island, I made a super busy vibrant neighborhood area with front yards etc and when I went to the “downtown” area where the shops and restaurant are, I got pop up that I was almost at my limit, I don’t have the biggest island yet so idk if the limit increases but something to keep in mind

I have noticed a slight difference between miis in the personality thing. Some are more formal like they will say “I am known as *insert name*”
Or they will take a little longer to fall in love.

I hear people often talking about the quirks under an optimized prospect, but thats not my playstyle. If it's not in the Mii's character to eat big, I wouldn't, maybe even small if I must. But It IS good to note that how I present each Mii will promenantly effect things.

i learned if you give a sad mii a loved food it completely wipes out their sadness bar. Maximus from fallout LOVES baked beans lmao

I set my husband's mii as my irl husband in my game and our miis fell for each other and married so I think it gives you a higher chance of them falling in love.

Light eater dose have a tiny use: it stops your Miis from constantly begging for food so they have other problems like friendship and romance gets prioritised. At least that's what I've noticed.

I put down a second restaurant and it enables more Miis to hang out at "the pubs" at the same time, of course. Maybe I should put like four of them next to each other for one big pub... or like a Bourbon Street kinda vibe. Hmmmm...

I've used the Small Eater quirk for character reasons in a couple places, like for one Mii who's an android and normally wouldn't eat at all. But yeah I certainly understand the major gameplay advantages of Big Eater.