Multitasking is BAD BAD BAD! So many recent studies have proven how bad it is. Yet we still do it so much!
Here are ways to get your daily tasks done faster WITHOUT multitasking, (Multitasking slows you down anyways!)

Do Each Task Until The end.

We start something; We get distracted, We start it again. We get distracted again, And nothing ends up doing!
Usually, if the task takes less than 40 minutes, I'll do it until the end. So I can remove it from my mind and my to-do.
For larger tasks I use the Pomodoro technique to knock it out faster.

BATCH Your tasks

Similar tasks can be batched; This makes it faster and easier to get more done. When I write Steemit posts, You may notice I post them all around the same time, This is because I open a bunch of windows on my web browser, I have the stock photos I Like to use open, And Grammarly open. Along with Evernote and any research, I was doing.
I try to write 4 Steemit posts per day, So I open 4 Grammarly windows, As I finish each post, I close the windows. So I can see my progress and how many posts I'm down to at the moment.
Then when I'm done writing for the day, I open Gimp, Clipart websites, and other programs so I can start to work
I don't just make 1 Tshirt design, Then Write a steemit post then make another design. That would be silly. I write my Steemit posts in one couple hour period. Then I do a couple of hour period of Shirt designs, and a couple of hours of drawing.
When you mix stuff, It can be easier to get off track, and that shift causes your brain to have to adjust, Which uses more time. This makes it harder to stay on task.

Know How Long It Takes To do Each Task

Knowing about how long things take, Is important when planning your day. If you do the same things each day, Time it a few times to see how long it takes you so that you can require a reasonable amount of work for yourself each day! If you don't know how long something takes, How do you expect to have a reasonable timeline? Short answer, You can't.

Get Rid of the Stuff You Hate The Most

As you go about your day, your motivation and willpower are in a constant state of depletion. You don't have an unlimited amount. Sure you can still attempt to "force" yourself. But eventually, your brain will get really clever at coming up with excuses.
Doing what you hate the most first, Will knock it out, And you'll have more enjoyable tasks the rest of the day, which will make it easier for you to feel better about what you are doing. You will be more likely to accomplish ALL Of your tasks instead of just some!

Ask for Help!

Don't be afraid to ask for help when you feel too overwhelmed. I recently had to start hiring some designers to help me get T-shirts done. Because I just had too much on my plate. There is nothing wrong with that. Sometimes our goals too big, and we can't possibly accomplish everything in our lifetime. But sometimes we can get others to help us out!