Scaling in/out: how do you manage the initial position size?

Still figuring out my scaling strategy. If you plan to scale into a position, say $AAPL, do you make your initial entry smaller than your normal full position size to leave room, or do you just go with your standard size and add on top if it moves favorably, accepting you might overexpose? It feels like there's a fine line between disciplined scaling and just chasing the move.