Why are y'all blaming the certified divers for the quality of instruction they did nor did not receive (or received but failed to integrate)??
If you have good tips to answer their questions, offer them. Along with helpful tips, recommendations to receive additional training--either paid for from an instructor or free from diving with better skilled buddies--only make sense.
Unless all of your commensurate skills were obtained during your lengthy comprehensive OW course (yea, right!) perhaps you just no longer have a recollection of how green you once were and how many of the skills that WERE taught were not immediately mastered.
BTW--ALL of the tips given so far were right enough to get this diver going in the right direction. If he can get down and stay down, 3 pounds more or less will not matter RIGHT NOW. As his skill improves and his instructor or buddy points out that he didn't need quite as much weight as he had on during the previous dive, he can shed a couple and by then maybe be comfortable enough in the water to make a COMPLETE exhale at the surface to make a proper descent.
NEWBIES--dive, dive often, dive with those whose skills and safety consciousness you admire and watch them while you dive together and ask questions. Accept suggestions and criticisms. And when you get conflicting advice from 2 GOOD sources, that means you are in the land of opinion and you should try out both suggestions yourself as well as asking each diver why they believe one tip is better than the other one.
Have fun. Dive safe. Stay well within your training and comfort level while you build your skills!
theskull