Sorry is this is rude but how do you make a living only working 3 hours a day? Are you products already established?
3 hours is a lot of work if done without distraction. I think the key is to make your work more mechanical and less creative.
I have a system that I have perfected over the years which helps me do this[1]. It's like a stupid step by step list where each item links to a document which is another stupid step by step list that I follow like a "Robot" for these 3 hours. When you do it this way, it makes it quite easy and 3 hours daily is more than enough to launch a small to medium size project in a month (I think there are less than 200 items in total and about 50% of it you can easily outsource).
When a deadline is coming up, I take a 10 minute "organization break" and list the actual, concrete steps that need to be mechanically performed in order to complete the task. I think the problem is that my mind tends to get hung up on abstract task descriptions and I start overanalyzing. For instance, "Design welcome page" will turn into a wasted day of messing around with colors, fonts, and layout positioning. On the other hand, "Add X, Y, Z to prototype welcome page" is a much more concrete task and it defines completion so that I can move on to the next task on the list.
(Btw, you could turn your nested-robotic-link-list into a quick webapp that I bet would get a decent number of users.)