I prefer doing cables w/o a cable needle unless I’m making large cables. Right now I’m making Calla without a cable needle. I use the method that is explained in The Knitting Answer Book by Margaret Radcliffe. I insert my right needle tip into the far stitches that will end up being first on my left needle. (e.g., For a 4-stitch cable, I insert the right tip into the 3rd and 4th sts on the left needle.) Then I slide all the cable stitches off the left needle. Since my right needle tip is holding half of the stitches, the only ones completely off needles are the ones that would normally be on the cable needle. Next I insert my left needle tip into the dropped stitches and move the cable stitches on my right needle tip back to the left needle. Then the cable stitches are twisted and ready to be worked. The only thing to remember is which side of the knitting to insert your right needle tip when you begin: 1) insert tip from the back for a left-twisting/front cable; 2) insert tip from the front for a right-twisting/back cable. If the pattern doesn’t mention which way the cable twists, here’s what to look for: If it says cable front, that means left twisting; if it says cable back, that means right twisting.
Grumperina does hers a different way: http://www.grumperina.com/knitting.htm.
Instead of working all the stitches at the same time, she splits it up. I had trouble with this method, but I’m sure there are those out there who prefer this method over the one I use. It’s just a matter of preference.