Scrum tasks, tasks, and more tasks

I find that I'm often letting my teams know some norms around Scrum and the process of a task-oriented system so I thought I would throw these out to the world. We sometimes loose sight of these simple things and get wrapped up in bigger, more grandiose ideas so consider this a Wednesday morning reminder.

• Don't assign tasks to other people. You don't want people telling you what to do because frankly I don't function that way and I don't think people work well in this manner (in general). One of the key principles of Scrum is self-organized teams meaning teams that decide what they need to do to get the job done, not others telling them.
• Don't claim tasks as your own but don't do work on them. I often see people stake claim to tasks in Team System (our Scrum tool) and set them to In Progress but they remain that way the entire sprint. It deflates the value of the system and just makes it look like the team is busy (to outsiders) but we're not really doing anything (or you can't tell what you're doing).
• Don't create huge tasks that take days to implement. My rule is generally under 4 hours. If you have an 8 hour task what you're saying is that, uninteruppted, it will take me the entire day to work on this. In reality you'll be interuppted, they'll be meetings, phone calls, coffee breaks and 8 hours of effort will probably take 12 hours of duration which means you have one task that spans 1 1/2 days and maybe even 2. So as a team member, you're saying to the your team mates, leave me alone for 2 days while I do this in isolation. That's not condusive to a good team effort nor is it helping anyone. If you see a task that's more than 4 hours, ask yourself if it's really 1 big task or 2 small ones? The other advantage to smaller tasks is that you might break something up into two 4 hour tasks and each one can be done by two different people, meaning you actually deliver value faster and isn't that what we're trying to accomplish here?
• If you already have something "In Progress" don't pick up a new task. I've been told that I have ADD and while I might (I do have many projects on the go, both at work and home) I try to manage it. Picking something and saying "I'm working on this" then turning around the next day and saying the same thing on something else just looks like you're trying to look busy. It's okay to grab a couple tasks at a time or grab a new one if one task is just waiting on something or needs a small collaboration say with the customer, but knowing that a task has 2 hours of work left, yet grabbing a new one and starting it without finishing the first is just plain dumb. Why would you do that? Would you wash half your car, then go and cut the lawn knowing your car is covered with soap? Even with ADD I wouldn't.

How do you eat an elephant? Easy, one bite at a time.