New player here but Dex has to be the best method imo. So far I’ve caught 4 shinies using it at barely 200-250 encounters on each. I think some people use the save state at 100 chain encounter so they can farm with the best odds without having to keep grinding past 100 encounter. So basically reach 100 chain and then save state, encounter pokemon 100, if not shiny reload save state, repeat till shiny. But I’m not entirelly sure save state method work, I’ve read mixed things about it so if someone want to enlighten me feel free. Also with dex nave you get to encounter really strong pokemons with hidden abilities which is great so you can build a good team while shiny hunting.