at first pick a bag, any bag, but not too big , you don't want to spend a week doing this makeover, something like that one
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then pick a pattern, any pattern, but not too difficult, you don't want to spend a week trying to figure it out, pattern like that one
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pick a yarn, any yarn, may be red. Knit a square (if fits your bag) with the pattern. just as big as half of a bag. make a rectangular bottom too, i forgot to take a picture of that, oops
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make 2 sides , sew them together and attach them to the bag
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crochet around the handles and there you go, bag is ready!