What are some actual ways to multitask productively?

I do believe you can take just one action at a time, and concentrate on just one thing at a time.

But if you can switch your attention among important bits of information fast enough to get clarity and /make decisions then your actions can set effects in motion that will continue while you take your attention to another task.
This is paralleled in project management where the manager gives instructions to several staffers who each are accomplishing stuff at the same time, and the manager is arguably getting all those things done too (and may unfortunately take all the credit for them).
Machines also let us delegate processes, pushing some buttons to start and returning to monitor progress.

So you_can_ get multiple tasks done at the same time, even if you’re only actually doing one thing at a time.

On a personal level, I think the key to multi-tasking most effectively is developing the sense of gating items in each of the tasks you’re managing. If some task that will take a long time is held up waiting for an action, then it can be expeditious to do that action and come back to other tasks after that’s set in motion.

I have more trouble single tasking. I can’t always do just one thing. It’s a running joke in my family that since I was a kid I can read a book, watch tv, and listen to the radio and know exactly what’s happening on each. My brain just always goes at warp speed.

I naturally skip between tasks (the AD/HD, I think), so I’ll set up two or three at a time and bounce between them. Especially computer-related tasks, though I do a decent job at work as well, where I have several concurrent manual tasks and no possibility of accidentally finding that book I was reading last week that got lost under the bed.

@Nullo I do the same thing; with the exception of the book being under the bed lol

The brain is capable of some parallel processing (carrying out more than one process simultaneously), but that all comes to a halt whenever any kind of decision has to be made. The decision making process is very resource-intensive, so other mental activities get put on hold.

Activities with which we’re very familiar don’t require much decision-making. They kind of “do themselves”, in that they simply demand a low level of monitoring while you execute well-rehearsed routines. These can be done in parallel. It’s a matter of getting comfortable enough with the routines that the executive function of the brain doesn’t need to get involved. Note that if a problem were to arise while those parallel processes are running, then a decision would have to be made, the executive function would kick in, and all that parallel processing would go to hell.

I find it impossible to do more than one thing at a time. It is much more efficient to do everything serially.

The best way is to set one thing up that will run itself, and then work on something that requires constant attention. Using my own day as an example, I start my computer up, and it takes 10 minutes to load all the settings. During that time, I set up the coffee pot. While those are running, I put my breakfast into the microwave to cook. Now my computer is ready to load up my browser, and as that is working my breakfast and coffee are ready.

I sit down and eat while I check my e-mails and other messages, then Fluther for a while. When I am finished eating, I rinse all the dishes from the night before and put them in the dishwasher. While it is running, I work on my computer contests (answer questions for points) and take an occasional break to go around the house and pick up the dirty laundry from each room.

When the dishwasher is finished, I separate the laundry and put in the first load, then back to the computer games while the clothes washer and later, dryer run. I alternate between my other daily tasks that way all day. If there is anything I missed on TV, I watch it on Demand or on a disc if my husband has copied it out for me.

If there are any phone calls, I answer them while I put my TV on hold and make appointments with the vet or a repair person.