(As an aside, my favourite type of cable needle looks like this. Wood, so the stitches don't slip, straight so there's a minimal amount of manipulation required, and with clever bulges at either end so the stitches don't slide off.
Back to cabling WITHOUT the aid of such a needle. In the following example, I have 2 purl stitches, then 2 knit stitches on my LH needle. I want to bring the 2 knit stitches forward and to the right, in front of the purl stitches.
1. I slide the tip of the RH needle purlwise into the 2 knit stitches that are to be cabled across.
3. Next I carefully ease the 2 purl stitches off the tip of the LH needle. IMPORTANT: I use my right index finger to immobilize them at their base, so they can't go anywhere and so they retain their proper orientation.
3. Next I slip the 2 purl stitches, now at the back, onto the LH needle, being careful to maintain their orientation.
4. Then I return the 2 knit stitches to the LH needle.
Here are the 4 stitches that were just manipulated, now in the correct order for the cable.
5. Finally, I knit the knit stitches, and purl the purl stitches, and the cable is crossed correctly.
This was an example of a cable crossing to the right and in front.
It's no more complicated to cable to the left. In this next example I have 2 knit stitches, then 2 purl stitches on my LH needle. I want to cable the knit stitches across to the front and left of the purl stitches. I simply dig the tip of my RH needle into the stitches to be manipulated from the back. Here are the steps, without any further commentary.
I hope this liberates you from digging in your purse for that dratted cable needle, at least most of the time. And pardon the closeups of my winter-roughened hands!