You can customize your profile by selecting a unique profile and header images, adding a name, bio, location, birthday, website and theme color, and by pinning a Tweet that other people will see when they visit your profile.
How to customize your Twitter profile
First, sign in to twitter.com website or open Twitter app if installed on iOS or Android. Then go to your profile. Click or tap the Edit profile button and you’ll be able to edit your header photo, profile photo, your name, Bio (maximum 160 characters), your location, your website, Theme color (only editable on twitter.com) and birthday.
Header photo: Recommended dimensions are 1500×500 pixels.
The profile photo: recommended dimensions are 400×400 pixels.
Format supported: Photos can be in any of the following formats: JPG, GIF, or PNG. (Twitter does not support animated GIFs for profile or header images). Twitter supports only JPEG, GIF, and PNG file formats. Profile photos with nudity will be removed. Check the size of your image to fit in your Twitter account. Maximum file size for profile photos is limited to 2MB.
Click or tap into any of these areas to make your changes. When changing a profile or header photo, click or tap the camera icon and select Upload photo or Remove an existing photo. You can choose to Show my Periscope profile through your Twitter profile (available if you’ve connected your Twitter account to your Periscope account). Click or tap Save changes.
You can customize your Twitter profile by adding your birthday. You can control who on Twitter can see your birthday on your profile by using your birthday visibility settings.
Twitter Header image gallery on Flickr
A big list of high-quality header images is available in Twitter’s Flickr account.
Twitrcovers
(www.twitrcovers.com)
You can find a good number of high-quality Twitter header images on this website. 
Recommended dimensions for profile images are 400×400 pixels. Recommended dimensions for header images are 1500×500 pixels. Twitter supports JPEG, GIF, and PNG file formats. Profile photos with nudity will be removed. Maximum file size for profile photos is 2MB.
Pin a Tweet to your profile
You can pin a Tweet to your profile so that when others visit your profile, it is the first Tweet they will see. Go to your profile. Find the Tweet you’d like to pin.Click or tap the icon located at the top of the Tweet. Select Pin to your profile. Click or tap Pin to confirm.
Unpin a Tweet from your profile
Go to your profile page. From your pinned Tweet, click or tap the icon. Select Unpin from the profile. Click or tap Unpin to confirm.
What do you think of it? Did you used a custom background on your twitter account and want to share some tips.We are happy to hear it from you.
