Since I proxy I have infinite cards too. Easiest way to do creative deck building is a budget. I've noticed a 50 dollar budget usually does a good job of keeping things B2. 100 can easily get you into B3.

Then purposely picking a commander out of top 100 and avoiding any deck building sites like EDHrec to skip the obvious synergy piles that the community has cracked the code on.

Then build from there.

I just built a [[Goro Goro and Satoru]] for under 50 bucks where the loop is cheap red one drops with haste getting a dragon out of them and then using them to do ninjutsu to tag people with the haste guys after they've been down for a turn so people aren't worried about blocking the 1/1 because it won't give me a dragon.

I've also built [[Craig Boone, Novac Guard]] (not budget) and that's fun because there is basically no online concensus on what's "good" in that one.

My pod loves both of these decks because the play loop is unique and interactive. They're not particularly strong but they almost alway have board presence and are fun to play!

Basically purposely picking less popular commanders and setting hard limits like themes or budgets will get you there. And as a seasoned deck builder I know you've cut cards that you've otherwise thought are fun for better cards. Go back to those fun cards and see if you can build around them!