when should you fish certain lures

When you feel like fishin'.

kidding.  Way too vague of a question. Can you narrow it down?

lol! I fish certain lures when i go fishing too.  ;D

        What types of lures are you refering to?

You sure made it tough to help out with that question, but let me give it a try.

I have three lures that I feel I have "mastered". The Fluke (fished several different ways), the jigs made for soft plastics, and the Carolina Rig. These are my confidence baits. I fish them about 85% of the time. I try to have a good working knowledge of and some confidence in several other styles of baits i.e., spinnerbaits, Jig & Pig, top water baits, swimbaits and so on. I am still trying to get some type of confidence in crankbaits. If you are looking for anything specific like a magic formula for colors, size, type, and rig under every condition. My suggestion would be to click on the Fishing Articles at the top of the page and start reading. That is the best thing you can do. You will soon find out why we can't answer your question.

It's easy to get overwhelmed with the choices.  To counter that, keep it simple...

http://bassresource.com/beginner/bass_basics.html