I thought about it for a minute and came up with a few ideas.
I apologize if I repeat ideas others have said I've not read whole thread.
I want harriet to ditch the mii masks and gain some new options. I want the player character to also ditch the nub hands and get.... actual hands. On a console like the switch I think there's no excuse to not give the player hands. The nubs are the best design choice for the 3ds because it can't show high detail, but trust me, they'll look weird in a fully hd enviroment, I think they already don't fit in with pocket camp. I want Harriet to offer nail colours and designs. These will not fade or anything like that, and you can change them once a day - even if you got a haircut you can change your nails, but you cannot change your eyes and hair in one day still... the reason? getting your nails done will act as a new friendship mechanic for harriet, just like talking to sable. Once you're at a high friendship with harriet she will do your nails for free, and offer more interested options like 'galaxy' nails etc, I think the nails should remain short to keep with the tone of the design, so it will really just be a tiny splash of colour. I thought of expanding this with makeup.... but I think makeup would break the tone of the game, whereas even little girls occasionally paint their nails. I'm not 100% sure how I would translate this for male players, male players could get their nails done if they wanted, but I feel many would not be interested. The only thing I can think of that could serve this same friendship role is having harriet style a small piece of the players hair, think of it like one piece of hair in the front of your haircut that you can get coloured differently from the rest of your hair. But I guess the reality is Boys are less likely to befriend a woman running a salon anyway irl.... so ... idk!
Other than that I want new tree species. These would act basically like the existing plain trees. Wouldn't it be nice to have more diversity in trees? So many players save their towns in cherry blossom season, but with different trees that flower at different times of year I think this would lead players to have a lot more options with the look and feel of towns. The gingko recently added to pocket camp made me think of this. I think the fruit trees could also look more like their irl trees, orange trees having darker deeper greener leaves, the trees blossoming the related flower to the fruits before the fruits appear on the tree.... little details to make the trees more unique. I also hope the trees are larger to create a feeling of the player walking UNDER the trees not merely beside them.
Trees I hope get added :
Gingko
Weeping willow
Japanese Maple
Camelia Trees
... and basically any other beautiful and unique trees they can put in the game.
I've seen some people do very interesting mods of the game and change tree appearance.... maybe the game could just have it as a default feature! I also want new thing, in the autumn I would like if leaf piles appeared on the ground, they would work similarly to clovers in that you can run over them and they won't disappear, but they will look pretty and make a satisfying 'crunch' sound when you run over them. I think it would also be an interesting way of incorporating mushrooms, as irl mushrooms love to grow in tree mulch... maybe you might trip over and pile of leaves and say something like "huh a mushroom was in here!" and it will be put into your pockets. I think it'd be cute and really emphasise the feeling of fall. I think in the winter too, some tree types should completely shed all leaves, with others retaining leaves - just like real life. Basically as much as possible I want players to have options to make their towns look unique and different using all the flora available to them. More plants! So many plants!
Also... no more rolling log! rolling log just limits a lot of stuff with spacial awareness because that's.... not how real life works. I think the rolling log is such a design flaw in the series. It's gotta GO!