Ordinarily, there is no contradiction between making plans for the future and trusting the Lord for the future. God uses our plans to accomplish His purposes, so we should not think that the plans that we make are necessarily opposed to faith in His providence. As the Lord gives us wisdom, we should plan, always entrusting these plans to Him for His will to be done.
Fasting places no obligation upon the sovereign God to respond in a way we have asked. Yet He does take special delight in us when we show our helplessness in fasting, and He will respond by giving us a greater knowledge of Himself, a deep sense of our dependence on His grace, and maybe even the specific request we bring to Him. Perhaps we would see the Lord move more mightily in the church if we fasted more often.