Introduction

If you haven’t tried it yet, you need to make careful consideration of adding a header image to your Twitter profile. Much like the Cover Photo on Facebook Timeline Pages, the header image injects a much needed amount of personality to your page, making it that much more attractive and easy to read.
In your profile page, the header image frames your profile picture, Twitter username, your listed name, and the description you’ve made of yourself. It’s another way to personalize user owned accounts. For corporate Twitter accounts, it is an aid in optimizing that real estate.

A few things you need to note for readability’s sake

The text is centered in the middle of your Twitter account. You’re better off using an image that has no details in the middle.
Furthermore, the font they went with does not come with its own shadow or outline effect to make it appear on top of whatever background. In other words, you have to avoid backgrounds with bright or mixed colors so that it stays readable.
Twitter layouts are different on mobile, with iOS and all the different implementations of Android to deal with. When Twitter launched this feature, it coincided with the release of updated iPhone and iPad apps, so those devices integrate the header image. However, the iPhone also changed the dimensions of the header image and the profile picture slightly. If you can double check how it appears on your and your friends’ smartphones, you should get their help.
Of course, the header image does not appear on third party apps like Hootsuite. The header image is not a replacement for your profile picture, so you still need to have a profile picture that will stand up on its own.
Some users inventively arranged the header image in such a way that the profile picture can align with the header image perfectly, Unfortunately, this effect is lost in mobile devices, so I find it hard to recommend this.
Generally, you are best off picking header images that are not particularly detailed, that will look good irregardless of the screen size you are viewing it in, and will appear attractive irregardless if the scale changes between it and your profile picture.

The picture dimensions

The picture needs to be under 5 MB
The ideal size is 1252 x 626, but at the very least, it should not go below 700px
I personally think you should decide what to do with your Twitter page, but if you want advice on making it look good;
Choose an image that will match your background.
Choose an image that will match your profile picture.
If you’re scared to screw it up, Twitter temporarily still allows you to remove the header and revert to the old layout.

How to add/replace your header image

1. From the Twitter toolbar, click the gear icon and choose settings. This will bring you to the Account page
2. From the Account page, click on Design. This will bring you to the Design page
3. From the Design page, scroll down and look for the “Customize your area” section.
4. Click “Change header” and proceed to add or replace the header image.
5. Finally, click “Save Changes”.

Some personal tips

Of course many people made up their backgrounds using Photoshop or GIMP, but most of us don’t know how to use that, so what o you do? Use Flickr, Wikimedia Commons or Google Image Search to find pictures in large dimensions.
In fact, desktop backgrounds can be easily reappropriated to the 1252 x 626 dimensions of the header image, but you have to remember that the image will be considerably shrunk. Try to find pictures at a ratio of 2 to 1.
Match the header image colors with the profile picture colors. This may appear self evident, but it is worth noting if you have a hard time picking a picture.
If you are not a professional, you do not have to try too hard. Get a simple picture that will reflect your identity. Take a picture of flowers, robots, a close up of your PS3, a landscape, whatever. Just remember the guidelines I’ve noted above and you should do fine.
If you are a professional, yes, when you make the jump you will want to invest in getting an illustrator to make you a good header image. Remember that profiles without header images use the old layout, which is not as great, but still looks OK.
If you are a graphic designer and you have not tried this out yet, get off your butt and do this. There is no end of templates and free tools out there to help you make your own header image.

Finally: A Confession

I have personally known about the header image for a while now and I have purposely made the decision not to add a header image. Why? Because I’m OK with the old layout. On a personal level, I do not feel like I have extra time to seek out or make a picture for that purpose, but even on my days off, I still do not feel like it.
So remember, at the end of the day, the header image is an optional thing. Twitter has played around with different ways of making the profile page look better, and as time goes on, we may see future changes making this one obsolete. We might even lost header images after a while.
If you do use Twitter for business, you should take the effort to add that header image. It is not so much an obligation as it is an opportunity. A really easy opportunity to brand your Twitter account, and one that is not as intrusive as Timeline was for Facebook.
What do you guys think of the header image? Would you make the jump? Share your thoughts in the comments below.