Occasional tag commentary notwithstanding, most of your Tumblr tags are likely to be short and to the point, identifying the subject of your post rather than adding your own two cents. Those are the tags that will show up in your Tumblr cloud -- a list of the tags you use frequently, with the most common ones displayed in a larger font. Tumblr doesn't natively offer a way to create a cloud, so you'll have to rely on one of several external services. Which you choose depends on whether you want a static cloud that shows your most used tags when you created it or a dynamic one that constantly updates.
Log in to your Tumblr account. Open the Tumblr Cloud website (see Resources) and then click "Generate a Cloud."
Grant the application access to your Tumblr account when prompted to do so. If you have more than one blog, you'll also be prompted to select the one for which you want to generate a cloud.
Adjust the various options to your liking and then click "Generate My Cloud." If you selected the "Post to My Blog" option, the cloud is automatically posted to your blog. Otherwise, the application will simply show you the cloud as an image which you can save and post to your blog manually.
Simple Dynamic Cloud
Open the Tumblr Tag Cloud Widget website and type the name of your Tumblr blog in the "Tumblr Name" text field. The website automatically generates a cloud.
Adjust the various options to your liking. The cloud automatically updates based on the options you choose. For example, you can choose to make the cloud show a maximum of 100 tags and only include tags used 20 or more times.
Copy the code shown and paste it on your Tumblr blog when you are satisfied with the look of the cloud. You can paste it in your theme's HTML code, in your description, in a separate page or in a text post. If you do the latter, though, keep in mind that the cloud won't show up on the dashboard -- your readers will have to open the post page for the cloud to appear.
Colorful Dynamic Cloud
Open the Pretty Cloud Tag Maker for Tumblr website, type the name of your blog in the "Tumblr" field and then click "Load Tags." Wait for the website to load your Tumblr posts and analyze the tags you've used . If you have a lot of posts, this can take a while.
Adjust the settings to your liking. You can change the color scheme, the fonts used, the size of the text, the size and density of the cloud and the maximum number of tags displayed, as well as the method used for choosing the size of each tag. You can also select tags to exclude from the cloud.
Click "Save Cloud," copy the code that appears and paste it on your Tumblr -- either in your theme's HTML code, in a text post or in a separate page.