One of the most useful cast ons is the Long Tail Cast On, also known as the Two-Strand Cast On. considered as a wrong side row.
Keep the tail toward you as you work this cast on.
Measure out a length of yarn for casting on. One method to figure how much yarn you’ll need is to wrap the yarn around the needle, one wrap for each stitch.
Alternatively, you may want to use two separate strands of yarn for this cast on.
Pull the slipknot securely, but not too tight. You don’t want to cast on too tightly or that will make knitting the first row very difficult and can cause a very tight sweater bottom.
Holding the needle in the right hand slip your left thumb and index finger between the two strands of yarn and separate them as shown. Hold the yarn that continues down securely in your right hand as shown.
Continue coming up through the thumb loop from underneath and pass the needle over the strand of yarn that is running from the top of the index finger to the slipknot on the needle. Pull this index strand into the thumb loop.
When working this cast on you will be casting on with one strand, and knitting the first row with the second strand.
For this reason the first row worked after the cast on should be worked as a wrong side row. If you’re working in Stockinette Stitch (plain knitting) you would purl this row, if you’re working in a charted pattern, work this row as the last wrong side row of the chart. This way you’re set up to work the first RIGHT SIDE row (the next row) as the first Right Side row of the charted pattern.
Note: For a looser cast on some prefer to cast on using larger needles or using two needles held together.