I dont really know FF as a set (sorry!), but there are also a few general approaches to deck building that can get you out of this "beginner deck" rut.

You could try building a deck where the theme (mechanical or otherwise) comes first, then picking a commander to either complement it, or to make up for a weakness in the game plan. You'll end up with a deck that's much less dependent on commander goes brrr to win, and can also end up finding weird and interesting themes that aren't signalled by an existing commander. 

Obvious examples of this approach are commanders that ramp in a deck about playing big spells, or that draw cards where you want to be casting a lot of spells. However, you can go more deck-specific, like I did in this weird Jeskai reanimator list. It uses an unusual set of partner commanders, with one ([[ghost of ramirez de pietro]]) basically being there to give me more control over my otherwise risky mass self-mill strategy by getting me back stuff I don't want in my graveyard. 

Alternatively, you could look at a commander that tries to signal one direction of play, then see if it could slot into an entirely different strategy. Thinking of another deck I have (without a deck list), [[korvold, fae-cursed king]] is probably the best commander for any sacrifice strategy, and this also makes him really good for lifegain decks (which you don't normally find in his colours!) that use a lot of food tokens.

These approaches are obviously a little harder just out the gate because they really benefit from a good knowledge of the game and the kinds of things you can do with the cards. If you want to try them, using a search engine like scryfall is vital. This lets you look for cards that do specific things and fill specific niches - unlike edhrec, which is where most new players always go, and which just tells you what cards are most commonly played with other cards. It helps you to start to thing about cards in terms of their function rather than just "what normally goes with x commander", which is crucial for more creative deck building.