Our top recommendation to wearing a chain and necklace together is to have the plain chain be 2" shorter than the pendant necklace. So, if you have a 20" plain chain we recommend you choose a 22" necklace to wear with it. You can still make the same length necklace and plain chain work as the pendant on the necklace will pull down the chain a little further than your plain chain is sitting, however we still recommend you choose a necklace that is 2" longer than your plain chain. In terms, of positioning you should wear the plain chain over the necklace for the best aesthetic.