After you crochet the top, lay the fabric of your choice over the crochet and cut fabric about one inch larger than the part you want to line. Pin in place with safety pins. Check to be sure you have it pinned to the inside of the top.
Tuck the fabric in about 1/2 inch as you hand stitch the liner in place. Start at the bottom and work your way up one side to the top. Start back at the opposite side of the bottom and work your way up that side.
Remove pins. Your top is now fully lined. Congratulations you did it!