Day 1 of M1. Anking deck is by far the best deck given the continuous updates and extensive tags. Use all the cards for a topic, excluding duplicates, during a block. Then suspend the non-“high yield” cards after a block. The Step 1 deck is around 30,000 cards without duplicates. If you do a high yield deck with all of Sketchy pharm, micro and pathoma, that is about 20k cards, add in the First Aid level anatomy cards in Anking (super basic) and cards that cross over with Step 2 (now the important test), and you’re looking at like 24k cards. That is incredibly doable if you start day one. Don’t listen to upperclassman that say to wait until second semester or even worse until M2. They almost universally regret what they did and are trying to justify it or they get behind and can’t keep up with a full deck.
Those 24k cards will be more than enough to pass Step 1 easily, but more importantly it will set you up with a strong foundation for clinical years, shelf exams, and Step 2. There are only about 8k unique cards in the Step 2 deck, so if you can do the crossover cards during preclinical, your workflow during M3 can be UWorld, minimal Anki with mostly mature cards, and then just show up well rested to rotations.
If you are keeping up with the above during M1-M2, you can add on the OME cards (the videos are free and super short) from the Step 2 deck during the relevant block. This will give you context for the clinical side of things, help you on in-house exams if your school tests clinical type questions, and further reduce your workload during M3.
The better foundation you can build during M1-2, the more time you will have during M3 to learn the clinical stuff without having to review the relevant basic science. With Step 2 being a make or break exam now, AND clerkship grades being more important than ever, any advantage you can give yourself during M3 is something you want to do.