You don't need to spend hours anymore to achieve the look of cross stitch, use a paint pen.
You can do this method on any glass surface. Glasses, candle holders, votive holders, vases , etc.
First thing to do is find yourself a template of a cross stitch pattern that you like. Think holidays and all the neat motifs there are.
Position the template inside the vessel using tape. With an extra fine tip paint pen, trace the pattern onto the glass. To repeat the pattern around the glass shift the template inside the vessel and trace again.
If you make a mistake you can merely wipe it off while it is still wet.
Any craft store will have the paint pens, and templates.