Stop. It may seem like a waste of precious minutes, but forming a plan will save you crucial time later on.
Get stuck in. Once you have a plan in place, be wary of 'action illusion'. What can feel like useful preparation (reordering your task list, again) could be glorified procrastination. Decide on your first steps, stop arranging and start doing.
Manage your energy. In a poll of US executives, more than half said Tuesday was their most productive day. Decide which days (and times) are your energy hotspots, then map tasks to match this curve.