Elements of a good To Do List (aka, set of goals): MAST
(M)easurable - Can you tell EXACTLY when you've finished it? Something on my to do list like " finish laundry" is easy to see; anyone could tell that it's done because all of the laundry is cleaned, folded, ironed and put away. But if it's something like "study for test", how do you know when you're done? Make it something concrete instead, like "be able to explain this process or recite facts x, y and z from study guide". Then you can check it off your list and know that it's done.
(A)ttainable - Is it a reasonable goal? I don't know about you, but I can't organize an entire room in a day. Sometimes I can't even get to the bottom of the pile on my desk. So I break it up into smaller, more manageable pieces. Then I gain momentum (Yes! I finished that whole section I said I wanted to do!) on what I get done, rather than focusing on how much there is left (Bummer. I wanted to do the entire garage, and I only did this one corner.). Putting too much on the list for the month, week, day, hour, etc, only starts the guilt trip, which we all know is not conducive to future productivity.
(S)pecific - This is very related to the measurable side, but takes it deeper to be sure you're not just saying, "I'm going to do the laundry". I gave the short-hand earlier: I know my laundry is done when it's washed, dried, ironed, folded and put away. But I need to set those terms when I start out, even if it's unconsciously like most of us do for things like chores or other repetitive tasks. So for the garage - do I want to clean out all the trash, or just rearrange everything? Do I have a certain way I want the system to work by the time I finish? It's hard to say I'm done if I don't know what I'm aiming for.
(T)ime-limited - I am TERRIBLE at getting stuff done if I don't have a due date. It's the curse of being a procrastinator by nature: I can work great under pressure, and not well at all until I have that pressure. It helps when my husband, boss or friends give me time lines for when they want things done, or help me stick to dead lines I've given myself.
One more: Partialize! In fancy-shmancy terms, this basically means, "break it down". I think the (K)eep (I)t (S)imple, (S)tupid works well here, too. If your goal for the month or week or day is to organize the garage (hopefully you have friends to help with the garage-in-a-day project, or a really small garage), then what are the small stepping stones you need to take to get there? Under the overall heading of garage, put in smaller steps like purchasing your storage bins, taking donation items to the thrift store or shelter, throwing out trash, taking specialty recycling items to their designated centers (electronics, paint, etc.), marking out your zones for different things to store, etc. Then as you complete each step, you mark it off the list. When all the smaller things are done, the larger goal is complete! And it's a lot easier to start with something small and work your way through that than it is to say, "Organize the whole garage? I don't even know where to start!" And it means you're not trying to do it all at once, which is very inefficient.