Interchangeable needles are a wonderful thing. Easy to come by, a great financial value, available in as many styles as there are knitters, and they can help you knit faster.
Once you’ve gotten all your casting on and set up rows out of the way, switch that left hand needle to one two or three sizes smaller than the one on the right. Your right handle needle is your gauge needle. The left one, you are just knitting the stitches off of. If the needle is smaller, the stitches slide more easily, and you’ll forego all that bunching. You’ll be knitting along at a good clip in no time.
Please note: If you are a left handed knitter, reverse the above directions. The smaller needle should be on your right side, instead.