I move around a bit between ITM, ATM, OTM but not much.

Mostly it's the nearest ITM strike at the nearest expiration (Monday, Weds, Friday) calculated on the SPY open.

The trade only going to last the day so I like to be in the money as it starts.

If there's a shift it usually comes because the SPY has outrun its open one way or the other. So have to move one or two strikes to accomodate a LOD signal.