You are a perfectionist and you like your cast-on stitches to match the 2*2 rib stitches, so have a cast-on of knit stitches for the column of knit stitches and a cast-on of purl stitches for the column of purl stitches.
Here I propose a simpler cast-on than the tubular cast-on: the 2*2 rib cast-on. This is a derivative of the 1*1 rib cast-on that I have already described here: Casting on stitches for 1*1 ribbing.
How to cast on stitches for 2*2 ribbing
Casting on in 2x2 ribbing allows for a smooth, attractive cast-on that follows the ribbing. It will be neat and create a beautiful finish. Make sure to maintain a smooth, even tension to avoid a cast-on that is too stiff and uneven.
Step 1 : make a slip knot in the wool and put it on the needle. Place your fingers between the two threads (thread attached to the ball on the index finger) so as to form a triangle (be careful this knot will be counted as a stitch, so you will only need to make a single purl stitch afterwards for the first two stitches of the cast-on).
Step 2: insert the right needle from back to front between the two strands on the index finger.
Step 3: Pass the right needle under the thread on the thumb from bottom to top.
Step 4: Pass the right needle back through the loop created on the index finger. Pull to form the stitch. Steps 2 through 4 create a purl stitch. Repeat steps 2 through 4.
Step 5: insert the right needle from bottom to top between the two strands on the thumb.
Step 6: Pass the right needle under the thread on the index finger from back to front.
Step 7: Pass the right needle back through the loop created on the thumb. Pull to form the stitch. Steps 5 to 7 form a knit stitch. Repeat steps 5 to 7 once.
Repeat steps 2 to 7 until you have the desired number of stitches. This will give you a cast-on for 2x2 ribbing.
