Great! I always like it when people use Pokémon they like, instead of just taking those that everyone else uses.
It depends on whether you want to use it in double battles or in single battles. In general, it's very slow so it could be good on Trick Room teams. You should probably get a Psychic move for Poison types (Psychic and Psyshock are popular options).
Off the top of my head, here's two sets you could consider. Remember that you can relearn Wish at any time, so you can go without it if you want.
Set 1 (using Wish): held item Psychic Seed or Misty Seed (both raise Sp. Def. when using Fairy or Psychic Max Moves)
-Wish
-Protect
-Moonblast
-Psychic/Thunderbolt/Thunder/Calm Mind/Nasty Plot
The last option depends on whether you want to set up, in which case Calm Mind gives you both power and durability and Nasty Plot gives you a lot of power, but no boost to durability. in that case use a Fairy offensive move, nothing is immune to it. You can choose not to set up and go with Psychic, but then you'll have to hit many times because Aromatisse's Special Attack is not horribly high. The usual trick here is to use Wish and then Protect next turn when you want to heal up.
Set 2 (Trick Room setup special offensive): held item Psychic or Misty Seed, or Expert Belt, or Leftovers, or Shell Bell, or strong healing berry...
-Calm Mind(for more durability)/Nasty Plot(for more power)
-Moonblast
-Psychic/Thunderbolt/Thunder
-Trick Room (or some other offensive move if you want someone else to set up Trick Room)
Pretty much the same notes as before. In Trick Room, Aromatisse is very, very fast and dangerous, especially after it sets up. You could make a good Trick Room team around Aromatisse.
Final word: beware of Steel types, have someone on your team to handle them as Aromatisse can't do much to them and they eat it for breakfast. Also watch out for people who use only very powerful and/or annoying Pokémon like Dracovish and Toxapex. Toxapex is horribly annoying and very common, but people usually copy one moveset for it that attacks only with Scald, so you could just beat it (set up, it's really tough). You might want Thunder for that thing. Dracovish is weak to Aromatisse, but is very fast and has a ridiculously powerful move so attack it with Aromatisse only with Trick Room up. People also really like to Dynamax with Gyarados and Hawlucha. Hawlucha is weak to Moonblast and Thunder or Thunderbolt are for Gyarados. If you have them, consider Electric Seeds for a Defense boost after Max Lightning.
Good luck!