User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-28303251-20130414002806/@comment-4555457-20130414050740

priority number 1 is cutting the tail off and carving that, you might get the gem and tada just finish it asap

after that just aim for the monster's weakspot (most are known), remember that your weapon choice does matter, a lance will more reliably hit diablos' stomach than a hammer will, if you can't get capture guru as a skill than be very careful and sure that you capture the monster - cutting tails and capturing has the highest chance of gems, i've heard that some monsters get a chance from breaking horns but i've yet to see a carve list that supported that.