Crankbait fishing is not just casting out a bait and retrieving it. There is much more to it then that if one is to be a effective crankbait fisherman.
First off the rod and reel choice is important. I like to use a moderate action fiberglass rod designed specifically for crankbaits. This type of rod allows the bait to hook up and give just enough so you do not rip the hooks out of the fishes face. You can do the same with your standard graphite rod. This can be accomplished by using a moderate action graphite rod as well, with a monofilament line. The fiberglass rod you can use braid, monofilament , or fluorocarbon lines
Reel choice is also important. With all the different ratio reels available today it can be very confusing at times. Your standard gear ratio for crankbait fishing is a 5:3-1 gear ratio this is not super fast, or super slow. The smaller gear ratio makes it possible to crank all day long with ease the smaller gears allows you to reel the bait in with less effort. Similar to changing gears on a mountain bike to ride up hill. You can even get lower gear ratio reels if needed. I run mostly 5:3-1's, but I also use a 3:8-1 gear ratio when cranking extra deep divers. This reel allows me to fish them all day long with ease.
Line strength, diameter , and style is also important. I recommend monofilament to all just starting out. It is the cheapest and most forgiving line to use. If one wants to gain a little more depth with the same lure I then suggest two things. First down size on line the lighter pound test the line, the thinner the line, thus the deeper the bait will dive. I would also suggest fluorocarbon as a second alternative to dragging a crank down deeper. This happens because fluorocarbon sinks, thus dragging the bait deeper. Now if you want your bait to run shallower increase line diameter. For example your using a crank that dives 3.5 feet deep on ten pound test and you want to make that same bait run shallower I would go from 10 to 17 lb test.
Braided line is a unique scenario, I only use it for lipless crank-baits when ripping them over weed beads. The braid helps the bait break free of the weeds cleanly and that very action triggers the strikes.