First, be sure it is actually a skipped stitch. Is there an empty hole? If so, then yes it is skipping. If it is just a long stitch with no hole underneath, then you are going faster than need be and that makes the stitch longer.
If it's a true skipped stitch, it is often caused by needle deflection. Needle deflection is when the needle flexes a tiny bit away from the hook as you are maneuvering the fabric around. The pressure of your movements pulls slightly on the needle, and if it pulls away from the hook, the bobbin thread cannot catch the top thread to make the stitch.
You can go up one size of needle and see if that helps. A larger needle will be stronger because it's a bit thicker... so may resist the movement away from the hook. Of course, if it's too big, the hook can hit the needle and you'll hear a tapping sound, which is not good. One or two sizes up like to a 14 or so should not be a problem.
You can try to move your hands smoother so no sudden jerks or sharp movements that could pull the needle aside. (You cannot see the needle moving aside, it is so subtle to the eye) Slowing down might help too, but smoothness is key.
You can use a larger thread with the original size needle, which will allow the bobbin thread to catch it better. You can try thicker thread with the larger needle too.
Let us know if any of these help!