Janet Perry (Nuts About Needlepoint) has come up with a simple but brilliant trick for staying on track while stitching an alternating stitch. She says,
This technique will work with ANY stitch that alternates and goes over only one intersection. That means T Stitch, Four-way Continental, Skip Tent, David’s Stucco Stitch, Tent-cross Check, and more I can’t think of at the moment.