If the destination you go to in Hong Kong has direct buses from Huanggang, you should look at those options too, even if the crossing is more messy and crowded. At least once you clear, you get a seat on the coach all the way.

And to answer the others, yes, the East Rail trains can really be crowded - morning and all evening - and unpleasant. I live near Yuen Long and use public transportation all the time, including the West Rail apparently, but East Rail is something else.

Anyhow, which is why many people prefer taking buses instead, myself included, even if may take longer and the cost basically the same. You have more chance of getting a seat, and even if it's on a packed bus (like taking 968 from HK Island back to Yuen Long), once I find a spot to stand, I am pretty much set all the way into YL. Unlike on the trains where you get shuffled around at EVERY stop for people to get on and get off.