thread a regular sewing needle with cotton and knot to make a small loop. Insert the tail of yarn through this loop and fold the end over. Place sequins on the needle and push down onto the yarn.
knit to where you want the sequin to be placed, insert RH needle into st tbl and wrap yarn around needle as if to k, slide sequin up to needle.
complete st, making sure the sequin is pulled through to the RS when you bring the RH needle through the loop of the stitch.