When you're creating a bundle you will get to the "Prepare" tab where you will need to set the signer fields.
Super Hotspotting is a new release that gives you the ability to click, drag and drop signer fields all in one flow. The field you click on will attach to your cursor and you will have the ability to move the field directly to the designated space on the document you're preparing. Click your cursor once more to drop the field box.
You can adjust the field box size by using the corners of the field box to control width and height.
Full Super Hotspotting walkthrough: