Shannon Error Magic style

I often have unspent mana during my untap step. Since I started playing UG I am seeing more of this. Some of it may be acceptable because I am holding mana back for counter spells which I do not need to use, but I am concerned that my mana ramp is not aligning with my deck and/or my draws.

Error Definition

The Shannon Error  is based on one of the Great Lewis & Clark explorers, who thought he had fallen behind, when in fact he had gotten ahead, of his team. So he rushed to catch up, which only compounded his problem by moving him further away from the rest of the expedition and further from much needed supplies.
From Shannon's experience, we can deduce the Shannon Error: the pursuit of a goal with great effort, the attainment of which is through less effort, not more; or, trying to catch up when you are already ahead.
My current concern is that I find myself often not spending all of my mana each turn. This happens in two ways--I create I have found that this happens to me a lot in magic. New to the game, I find myself drawn to large Timmy creatures that have clearly defined rolls on the battlefield.
Thus, I am a big fan of any thing that encourages Mana acceleration so that I can get these guys out as soon as possible.