I always want to be careful with diet recommendations because everyone is so different / has different triggers (for example, tomatoes might make one person flare but are fine for another). With that being said, an anti-inflammatory diet is a good place to start. In addition to avoiding smoking and alcohol, this could mean trying to go without gluten, dairy, corn, soy, etc. and seeing if you notice any improvement. Caffeine is cited by many folks with psoriasis as a trigger but, like I said, doesn't bother everyone! You could try cutting it and see if you notice improvement :) Granted, any improvement you'll see with diet will indeed take some time. Good luck!

p.s. caffeine makes my anxiety worse which in turn makes my psoriasis worse so I try to have less of it and do tea instead of coffee

have a look at https://www.livestrong.com/article/472231-the-p... - I found it helpful

I quit drinking coffee during a big flare up. And it helped me bc my body was able to calm down.
Drinking now again bc life is to short 😉 just make sure not to drink after 2pm.

I drink coffee since last one years and it helps for my liver.

Smoking has been linked to psoriasis, I have had several patients who were heavy smokers now diagnosed with plaque psoriasis. As a psoriasis sufferer myself, I can tell you that alcohol always makes my skin flare, even after a few days. I did some research into it and from what I've read the clearer the alcohol the better. I liked a glass or two of wine on the weekend, but it's just not worth the aftermath. I'm going to try organic wine with no sulphates.
Good luck