Consistency is the most important element of overall success. There are a myriad of smaller elements that come together to finish the battle (so to speak). If showing up is winning more than half the battle then what is the other battle and how do you win it?
Good question. The other battle is making sure you are doing something worthwhile when you show up. Showing up is enough in the beginning. Just doing something other than sitting all day is a great start. However, it is necessary but not sufficient. (I haven't heard that phrase since my high school sophomore Physics class. I'm so pleased that I can finally use something I learned in high school!)
I see a lot of people who show up at the club every day to workout. That's good, don't get me wrong. It is important to establish a habit and a routine. However, they have gotten into their routines and don't vary what they do.
They do the same exercises with the same weights in the same order on the same day. They also do the same cardio routines at the same settings for the same time on the same day. There might be small variances from those routines, but generally that's the way most people workout.
After a few cycles through that type of workout, their body has reached the maximum amount of fitness it can reach. It will do no more and in fact...it will start doing less! You see, as the body becomes more fit, it can simply do more. If you don't make it do more, it won't. There is no encouragement to become fitter.
Since we are all on the decline curve, the more we do, the more we extend our decline curve. However if you stop making progress on your curve it catches up to you and before you know it, you are, at best, on the decline you would be if you were on the Passive Lifestyle curve. (See below)

You have to keep pushing your body to do more in order to keep yourself ahead of the curve. We talked about this curve earlier this year, so you will remember how important slow steady progress is in meeting your fitness goals.
You have to continually challenge yourself to do just a little more than you did last time. I'm not talking about huge improvements, just small consistent improvement. You are not going to make improvements on every workout, but every workout should prepare you to do better in some way the next time.
Let me define what doing better means: doing better simply means doing something just a little better than you did it last time. You may have cut your time by five seconds; added 2.5 lbs more weight; added a second or third set of exercises; noticing that you did something better the second time than you did the first.
If you haven't mastered consistency yet, please master that before you move on to improvement. I see people who aren't consistent trying to improve and they get frustrated because it just doesn't work that way.