I'm sure you could spend money on knitting tools which accomplish the same thing, but this is the quick-and-dirty method. I'm using a 40" long circular needle to hold both fronts of the Augusta Cardigan, and a gallon-size ziploc bag to hold 2 skeins of worsted weight yarn. Before casting on, I cut the 2 corners off of the bottom of the ziploc bag. I placed 2 balls of yarn in the bag, with an end from each ball threaded through each cut hole. I closed up the bag, and cast on first one set of stitches. Before knitting those, I cast on a second set of stitches. Now I am knitting across both sets of stitches before I flip my knitting over, and if the yarn ever begins to tangle, all I have to do is flip the plastic bag over. This method has the added bonus of decreasing the amount of pet hair that gets knit into the sweater as well!
Are there any techniques you've learned recently that you think are worth passing on?