Use

Sketch a kitchen island

Drop a proposed island into the room; walk around it to check the flow.

Sketch the island footprint on the actual floor at the size you’re considering. Walk to the fridge, the sink, the range — you’ll feel immediately whether the aisle is too tight, and you can nudge the island until it works. Same technique for any large floor-mounted piece: a conference table, a retail counter, a workshop bench.