Lure action and color has to match the forage at the time. The most effective lure you have will be the color and have the right action to trigger a strike. Depths may have to be changed several times a day, your lure has to be kept in the strike zone. Adjust your bait depth to the depth of the fish. Speed changes the depth and action of your lures.
Direction is important only when the wind is involved.
Trolling with the wind makes it much easier to control your boat, plus the action of your lure is enhanced by wave action working with your planner boards. They surge forward, then drop back with each wave. The wind speed affects your trolling speed, at the same time it affects the size of the waves and the action of your lures. Like I said before, successful trolling is not as simple and as easy as it may seem. It takes a lot of good equipment and experience.