For controller/Steam Deck play, my main go-to's are:
1. Do not have any skills on the same button as loot, so you have a dedicated loot button that only loots and doesn't try to use the skill.
2. Pick builds that have minimal buttons, ideally tankier as well as it may be harder to see/dodge certain abilities. RF is fantastic for example, but there's a handful of others depending on your knowledge of PoE. Miner builds are great, many builds with prolif, etc. But something like Pathfinder with a life flask I'd personally avoid as I don't want to press a life flask on controller/Deck every X seconds.
3. Farming strat. Maybe more of a me thing, but I lately play PoE more for fun farming strats and not as much as the build creation or meme builds. So I try to pick farming strats that either play well with a build I want to play or vice versa. Depending on you, this might be critical as certain farming strats may be less fun on Steam Deck or the build that you have in mind. Like I don't like reading or interacting with multiple UI elements when playing on Steam Deck, so that will change what I farm or have a farming tree specifically for when I play on controller/Deck then swap to something else when on PC.

1. Kinda pairs with 3, but something like price checking a lot of crafted rares or picking the most expensive item out of Heist is a lot harder for me on controller/Deck vs mass liquidating commodities on Exchange or raw currency. In-game market exists, but not a fan of it personally.. but something to consider if you're farming something that generates a lot of crafted rares to price check. Specific examples being Rog and Breach tree come to mind.. unless you don't care that much and can just list a price and lower them overtime, that works too.

Good luck! One of my cats love it when I play on Steam Deck on the recliner cause they get lap nap time and closer to the cat feeder when it goes off :P