Imagine the question mark when approaching 1st. It’s important to note that it doesn’t matter which foot you use to tag the INSIDE of first base. What matters is you stay in stride. You can use your inside or outside foot – as long as you don’t stutter your steps when rounding. Every step/second matters and how you round this base could be the difference of being SAFE or OUT at 2nd base.

Good tutorial here from isport.com https://m.youtube.com/watch?v=Hy5eE4Ac2mk