You need to make the measurements of the garden island you want to lay bricks for. Take a measuring tape to determine the perimeter of the existing planted bed. You can use a garden hose to configure the shape of the brick border you desire to make and can make modifications into it until you are pleased with your design.
Now use the powdered lime or spray paint on the grass adjacent to the garden hose, making an outline of the shape you have to brick later and then remove the hose.
Dig out the marked border for laying the bricks. Note down the width and depth of the bricks to be laid and then dig the ground 2 inches more than those dimensions. Make a trench in the ground and level the soil within it.
Apply a 2-inch layer of sand or crushed rocks into the trench to form the foundation of the wall you are about to make within the trench. Rake it smooth and make sure it is fully levelled.
Now put the bricks into the trench and tamp them to nestle into the sand. Make sure you have initially placed the bricks slightly higher than the level of the surrounding soil, as the bricks will settle down later in the trench when you tamp them. Keep applying brick until you have completed the circle or rectangle (whatever shape you are making). Any adjustments in the size or shape can be made with the last few bricks easily.
You can sweep sand and fill in the gaps between the bricks you laid. If you have used the landscape fabric, trim the excess of it at the edges using any knife.
At the end, you have to rake soil on the garden side of the border towards the bricks. You can plant and mulch now!