Quick question about raising Skill.

The only two stats that are missing heavy drills are Life and Skill. Life increases in Pull and Swim, not to mention Errantrys, so raising life isn't that bad.
But on the other hand, Skill. Is there a trick to raising/maxing skill other than Shoot?

Drugs lower lifespan so that's not always a great idea.

Any help? Thanks.

Generally, I use it as the LD in a method, even if it's only used rarely. If you have patience, you can reset tourneys so that you get Skill as part of the post-battle stat gain.

Is it a good idea to raise Skill in a monster's prime or not?

That kind of depends on your method and how many weeks you think you need to raise the monster. I like to use Prime to raise the stats a monster isn't good at.