The reason the commercial references are so loud is that they have very little headroom – the average level is so high that there’s not much room for the peaks (which have been squashed down). When mixing, however, you shouldn’t worry about headroom on the mix bus. You need to give yourself enough headroom that you can focus on the task of mixing – getting the balance between the different sounds right. Wait until mastering before you tackle the “mastering loudness” problem.
If you try to mix at commercial levels (with extremely low headroom) by using a limiter on the mix bus, you’ll have an extremely difficult time of it because every small change you make to a sound will change the other sounds in noticeable and largely unpredictable ways. For example, if you turn up the vocals, the bass might become quieter (because everything becomes quieter). Noticing the bass, you turn it up, which might make the whole mix more distorted (particularly if you’re using saturating processors on your mix bus). It also causes problems because setting a channel to solo causes it to sound very different to how it sounds in the mix (because it’s being modulated by the other channels).
To make sure you have enough headroom at mixing, simply turn your speakers up. Turn the volume up much higher than you would have it for regular listening. Don’t use any processors on your mix bus. Your mix will end up “quiet” (because it’s much further from 0dBfs than your commercial references), but don’t worry. Mastering is a separate process, and one of the purposes of mastering is to bring the overall volume up to its final level.
By doing this, you are free to focus on the mix.