Buttonhole Techniques

• Eyelet buttonhole -- Work to desired buttonhole location, yarn over
  Yarn over
  In knitting, a yarn over is technique in which the yarn is passed over the right-hand knitting needle. In general, the new loop is knitted on the next row, either by itself or together with an adjacent stitch . The yarn-over may also be dropped on the next row, producing a longer stretch of yarn...
  
  , decrease
  Decrease (knitting)
  A decrease in knitting is a reduction in the number of stitches, usually accomplished by suspending the stitch to be decreased from another existing stitch or by knitting it together with another stitch.-Methods of Single Decreasing :...
  
  .

• Vertical buttonhole -- Knit to desired buttonhole location, attach a second yarn and begin knitting with this yarn; knit the two fabrics
  Knitted fabric
  Knitted fabrics is the third major class of fabric, after woven and nonwoven fabrics.-Elasticity, thickness and warmth:Compared to the other two classes, knitted fabrics are much more elastic, which accounts for their historical use in stockings and other clothing that requires changes in shape...
  
   flanking the buttonhole independently until the work reaches the desired length of the buttonhole. Rejoin the two flanks, drop the other yarn end, and work as one again.

• Two-row buttonhole (horizontal) -- Bind off an appropriate number of stitches and cast them back on in the next row. The yarn is usually woven
  Weaving (knitting)
  In knitting, weaving is a family of techniques for introducing extra yarn into a knitted fabric without knitting them. The extra yarns almost always follow the horizontal rows of knitting and, if visible, resemble a woven texture. Thus, with sufficient force, a woven yarn can be pulled out of a...
  
   into the bound off
  Binding off (knitting)
  In knitting, binding off, or casting off, is a family of techniques for ending a column of stitches. Binding off is typically used to define the final edge of a knitted fabric, although it may also be used in other contexts, e.g., in making button holes...
  
   stitches, for reinforcement.

• One-row buttonhole (horizontal) -- Work to where you want the buttonhole to be. Slip next stitch, move yarn to the back of work, slip second stitch, pass first slipped stitch over the second, slip next stitch, pass second stitch over the third, and repeat until desired width of buttonhole is reached. Turn work and, by using the cable cast-on
  Casting on (knitting)
  In knitting, casting on is a family of techniques for adding new stitches that do not depend on earlier stitches, i.e., stitches having an independent lower edge. In principle, casting on is the opposite of binding off, but the techniques involved are generally unrelated.Casting on can also be...
  
  , cast on the number of stitches bound off plus one. Turn work again. Slip the next stitch to the right-hand needle and pass the extra cast-on stitch over the slipped stitch.