...cull your offensive playbook to the 25 or so most effective plays over the last 10 games.

If they're averaging 3.3yds plus, I'm on to a winner.

I'd also add in 5 or 6 plays that haven't been used at all in the last 10 games just to try them out.

My view being that it's better to have fewer than 40 plays that work rather than giving the AI the opportunity to call one's that are proven to not work with the roster I have.

And if you want my advice....meh....I got nothing....and my record proves it...lol.

A good player has high numbers in 90% of their desirable stats.
A bad player doesn't have high numbers anywhere.

You are better off picking players with low numbers in most of their attributes, but with 1 or 2 rated very highly than someone who is 70ish across the board.

...spend 20-30 hours total brainstorming and designing the team rebrand.

Nah, but really, I would sit down with the depth chart and have an honest conversation about the team's roster needs. Think in terms of position groups and purposes. Which groups are thin on talent? Which groups are stacked beyond bare minimum starters? Can you convert any of excess talent to fill in where those thin spots are?

And when I say honest, I mean two things. You need to be realistic: You can't expect all your starters to be rated in the 80s and 90s, and even if someone overperforms their low rating, you still might want someone more formidible. You'll never have a perfect roster. You also need to consider the future: anyone on the retirement track doesn't count for planning, and succession for anyone a year or two away from the track needs to get pencilled in on your to-do list.

Once you know what you need, then you take stock of the what you can spend on them. Excess talent? Trade them. Stars approaching retirement? Trade them. Draft picks? Trade them for someone else's excess talent or take your chances on the draft. Low-end players who are getting upgraded? Don't waste anyone's time trying to trade them, just cut them and get on with your life. Though with deeper position groups--think d-liners--sometimes it's worth keeping a player you're planning to cut if you can get some value trading the worst player you'd otherwise still keep.

Once you get on top of your weakest and oldest groups, it's a matter of maintenance. Sure, you can work in a cycle of sitting on a roster until its past peak, hold a fire sale, and go into rebuild mode. But that's risky; one bad year of trading and drafting can break you. Instead, think of it as a constant process: stay a year or two ahead of players declining so you and your trade partner can still get some value out of them, always have some good rookies bubbling away on the back burner so that they're ready for primetime when you need them, give yourself enough freedom in your needs that you can draft to the strengths of that year's draft class rather than be left scrambling for a position with thin offerings.

The key is to never be content, to never consider your roster 'finished', there's always a move to be made.

Branding is important, though.

... make sure the plays match the players.

It's a video game, what works in real life doesn't necessarily translate to MFN. If you have a great QB, lean towards passing. If you have 1 good RB, be wary of choosing a 3 RB play. Just make sure the plays are something that the team can pull off.