1. Keep it simple!
Especially if this is your first big cross stitch project, choose for simple and small patterns.
We cannot say it enough. Really keep it easy. On linen fabrics you typically stitch over 2 threads. This means that if you have a 28 count table cloth of 200 cm (~80″) x 140 cm (~56″) your outside borders might easily be about 1000+750+1000+750=3500 stiches long. Adding a border of 5 stitches heigh will result in a total of 17,500 stitches to make.
When you pick a simple and small border pattern it is easier to repeat the patterns and to make them fit for your table cloth.
2. Add new details every year
If you use a simple geometric border pattern you can always add extra rows an decorations in the next year. The smaller your border the quicker it will be to finish.
3. Start stitching in the middle
Start stitching in the middle of the longest part of your fabric and work towards the edge. This way you ensure that the corners of your borders end at exactly the same spot on both sides.
Also for decorations on the topside of your table cloth start stitching in the center of your fabric. You can find the centre of your fabric when you fold your fabric twice.