Justin, it's fine that you put your own spin onto the exercise but in the future you need to practice the exercise exactly as described, for numerous reasons.
The idea isn't to make a Qi ball, it's to channel Qi to the hands and fill up the hands with energy. Also, the exercise should be done solely with Yi (intent), leaving visualization out of it. This is a combination of focus, concentration, body awareness, tactile feedback, and intention. You should try to move energy using solely intention at first, leaving visualization out, because it can become an unwanted crutch. Remember this:
Yi, or I (pronounced "ee" either way), is a concept that is rather hard to translate into English, in the same way that Qi or Jing is. It's a unique concept, and has no English equivilent word. Yi is often explained as being intention or willpower; it is much more than that. Yi is an equal combination of willpower, intention, focus, concentration, physical movement, and doubtlessness. That is the complex part of Yi- you must do all of these things at once for the best effect!
Willpower is strength of mind and determination. Intention is determination to do a specific act in a specific manner. Focus is putting your attention on a certain thing. Concentration is a closed or fixed attention. Physical movement, though not always needed, is moving in a prescribed manner that supports the qi flow. Doubtlessness is having total confidence that what you want to happen will happen. All these things together make up Yi. At an intermediate level, Yi becomes unconscious, to the point that you simply have internal control over your energy- it becomes as easy as lifting your arm or turning your head. At an even more advanced level, Yi is refined to the point that the energy just moves without you noticing it. At the level of a master, there is no Yi! Whatever happens, happens beyond conscious thought. This is referred to as wuwei (non-doing, Chinese), or mushin (No-mind, Japanese).
I'd suggest trying the exercise again leaving out the visualization and "ki ball" ideas. Don't let this demotivate you. The idea is to build up a strong connection and control of Qi through mostly thought alone.
I'll post my experiences now.
I started with Dantien meditation for about 10 minutes. After 10 minutes I felt very calm, I felt energized. I felt a large amount of Qi in the Dantien and the spine, and a swirling sensation in my head (as is usual for me). Anyway, I made the hand sign, touching my thumbs and index finger together. I was in a seated posture, and my arms were at shoulder level. I closed my eyes and began to meditate, focusing on the palms of the hand. I affirmed to myself, "I am going to fill my hands up with Qi". I focused on the hands and began very deep breathing, with the intention to gather Qi in the hands. As I did this, I could feel Qi moving from the Dantien, up the spine, and up the outer arm meridians to the laogong point in the hands. I was not consciously guiding the Qi from the Dantien, rather it was moving on it's own to follow my focus on the hands. After a while, my hands became very warm, and I had a strong magnetic feeling in the palms. My hands felt heavy. The hands began to tingle strongly, almost like they do when your foot falls asleep. As I continued, these sensations grew and even began to encompass the forearms and part of my upper arm. After a while of this, I decided it was enough, so I opened my eyes and stopped. I noticed that my arms and hands had lowered from shoulder level to about the level of my chest while I was doing the exercise.