Since we've hosted so many Christmas Day dinners over the years, I have a number of pics of past ones that I've done, plus a couple that you can use with your mason jars.
This one was using some of my Santa collection:
And this one was using 3 plain glass fish bowls, aritificial snow, tiny battery powered lights and candles, and small figurines from Hobby Lobby. In between, I used a couple of my Nutcrackers and tinsel trees. The kids that year especially loved this one:
Below is a 'centerpiece test run" before the big day. I think that year we had 11 on Christmas Day here, so more plates and a table extension then.
The next year the young children weren't going to be here for this one, so I used my ceramic birds inside the fish bowls, with other decs between them:
And, another year I got an idea off Pinterest to use tall clear glass vases. You could possibly use your mason jars for this one. I filled the vases with fresh cut pine, 2 or 3 small pinecones, and a few fresh cranberries. I then added water to each vase and a small floating candle. They turned out wonderfully, but I can't find my pics of them, darn it! Anyhoo, here is one of the Pinterest pics that inspired my centerpieces:
And, finally, I just found this photo on Pinterest of painted mason jars. I love this idea! There were several variations of this one, all very festive.
Q