That depends upon the kind of loops that you're looking for.
You can knit with two different size needles, one much larger than the other. The larger needle will form larger stitches which will look like loops when unstretched.
You can knit a stitch, loop the working yarn over your middle finger, knit the next stitch to anchor that loop and remove the yarn from your finger. You need to note where your loop was placed on your finger so that you can make all the loops a uniform length.
Is there another loop that you were thinking of?