Many stitchers like to baste the grid lines on their cross stitch fabric before they start a project. Usually the lines are five or ten stitches apart. This can make counting much easier, and allow you to skip around to different parts. However, it can be difficult to get the grid lines out after the project is finished. For me, this is a deal breaker. I recently saw a photo of someone's quite large cross stitch project, which would have been several months of work. It was beautiful, except you could still clearly see the red grid lines even after it was framed. I would be ill, and I know very well that after a few months of agonizing it would end up in the trash.
One alternative would be to take the basted lines out before you stitch the adjacent stitches. My approach is to start in the middle and gradually radiate out from there. Sometimes though, you have to take a leap across the fabric. I know that once I start counting above 10 I will not be accurate, so I will use a temporary gridline just to count out the space correctly. It looks like this:
|Now you see it...|
|...now you don't!|