At its best:
Make a few holes in the polythene lining of your basket, to allow for drainage.
Fill the basket with multipurpose compost to just below the rim.
Space the strawberry plants evenly around the edge of the basket.
Strawberries in a hanging basket not only look great, but will provide you with rich pickings of fresh fruit over several weeks.
Water the basket well to settle the compost and encourage the roots to grow. Start feeding the plants once flowering has started. Hang the basket in a sheltered, sunny spot to encourage pollinating insects and help the fruit ripen.