With a direct link.
Use the little yellow square icon with the two mountain peaks and sun, its left of the quote icon. Then insert the image address. I used the paper clip icon to upload the screen shot above, then attach it to my post. Then you can preview your post and click on the attached image link, it opens in another window, then copy the URL and use the yellow image icon. Paste in the address and voila, your image appears in the post.
Here is a video
of how I do it without photobucket, like the image above.