Start with clearances
Measure from the island edge to cabinet handles, not only wall to wall. Consider a dishwasher door, oven door and people standing at a worktop. Seating needs extra space behind stools.
Give the island a purpose
A preparation island can be simpler than one with water or cooking. Deep drawers, serving space or breakfast seating may provide enough value without moving services.
Consider a peninsula
When the room is a little too tight, a peninsula fixed to one wall can offer worktop and storage with fewer circulation routes around it.