If you have a big island that can accommodate many people, consider using full benches. The benches can be with or without backing to allow for more comfortable seating.
Allow adequate countertop space on both sides (left and right) of the kitchen island if a sink or cooktop will be used. Include at least 15 inches of countertop space on each side, and if your kitchen is large enough, allow even more space. You can never have too much countertop space in a kitchen. Also, rounded countertop corners help protect everyone from bad bruises -- this is true about all kitchen countertop corners.
Budget : Setting a budget out front can be beneficial if you have budget constraints. Having a budget to work on, you can easily adjust the types of material to be used or length of wooden planks to be purchased accordingly before ordering the materials.
Plan the height of your cabinet appropriately. Since most islands will have at least two stools or chairs pulled up to the surface, you may want to think about the seating or stools first. There are two kinds of bar stools with one being much higher than the other. Unless the island will be used primarily for family eating, there really are no hard and fast rules on height. It does not have to match the height of the kitchen cabinet, but often does. If it is not going to match it should be taller in most cases.
installing a kitchen island cabinet
kitchen island cabinet layout
kitchen island cabinet design