Assemble your base, your pallet candle holder to the size you would like according to how many candles you want on each piece. Stain the wood to the preferred shade, seal with polyurethane (your choice of sheen, i.e., matte, semi-gloss, etc.). I use hooks that are found in the curtain section; they are called curtain rod supports....I call them hooks! Drill small holes in the lids of the mason jars, exactly across from each other; sometimes I use four holes for four chains. Put the chains in the holes, put the lids on the jar, hang them on the hook!! It is just that easy.
Sometimes the candles do not want to sit level in the bottom of the mason jar, in that case, you can use aquarium rocks or sand in the bottom of the jar to make it easier to level the candle. Plus the sand or rocks can add color where desired.