I'm an absolute beginner, having only been working on learning Japanese since I got here a few months ago, but due to the nature of my work I might have some insight for you.
First, what Nekojita said is absolutely essential to remember. 2 hours per week is less than 1.8% of your waking time. Practice is essential though the kind of practice is even more essential. It should be fun and relate specifically to your current goal.
Second, knowing what outcome you really want is important. For myself I want verbal communication at a level which allows me to interact in my everyday life in Japanese. I don't know a single kanji and I don't currently care. It's not part of my outcome so I don't work on goals which relate to kanji learning.
Third, having short term, achievable goals is how an outcome is reached. For myself a recent goal I achieved was understanding the various choices in the yogurt aisle by having a conversation with a store worker entirely in Japanese. A recent goal I did not achieve was learning about the bunka kyokai in my cho by going to my cho office and having a conversation entirely in Japanese. You can see how these are goals specifically relating to my outcome.
Fourth, having strategies to reach those goals is necessary. This includes what kind of instruction you're getting and what kind of practice activities you're doing. For myself I chose to use a teacher who uses CI (well, one who is learning CI since I can't actually find one who knows it yet), and to focus my practice on listening comprehension since by using auditory bombardment to strengthen my receptive language my expressive language will take care of itself.
Finally, having measurable criterion which will show when an outcome is achieved is essential. My criterion is that I will use adult level Japanese in my daily life to hold typical everyday conversations including expressing wants and needs, commenting, and stating concerns over 30 consecutive days. In that criterion there is what I will do, when I will do it, and for how long.
So, create an outcome, determine what criteria will be met to show that the outcome is achieved, develop a goal designed to take a step towards that outcome, and build strategies which can be done daily and relate specifically to achieving your goal.
Hope this is helpful.
