Tablecloths!

The problem with tablecloths, in case you were wondering, is the middle. I know that I need to sew away from the middle (that is some sort of cardinal rule of sewing, is it not?), but I still end up with fairly lumpy middles. This first example was a total nightmare, as I did not account for this until way too late in the game:
The only way to solve this problem was a good centerpiece, so the tablecloth sits with a
lovely Vinca in the center at all times:

I wanted to work with this same pattern and have another go at it when I decided to make a table clothe for my mom. I was using my lovely new fabric from Bolt, so I did not want to screw it up. This time, I did not have the center pieces to cross over each other, so I sewed out from a central piece of fabric. I left about a half inch on each side, so I could fit in the 4 squares. I like the results, though there is still a slight bump in the middle. It is a considerable improvement from my last tablecloth, however:












My questions that remain are -- how to make the seems on a tablecloth so slight that they do not disrupt it laying flat? Also, what other patterns might a use for a table cloth? I am not sure how funky to go with tablecloths? I am thinking that, unlike a pillow, a few big pieces of fabric is better than a lot of pieces together? If nothing else, this will cut down on bulging seems.