Instead of opening up iMessage everytime we want to compose a message, we will make use of the “Share” option found in almost every application to fire up iMessage instantly. For example, to quickly compose an iMessage in OS X, select any file or photo and right-click it:
Select “Message” from the Share menu.
Now, simply delete the attachment by using the “Delete” key on your keyboard, compose your message and send it to whomever you want.
For all you iOS users out there, select your file (a photo in my case):
Click on the “Share” menu in the lower-left corner, and select iMessage.
Delete the attachment via the backspace key on iOS’s virtual keyboard, compose and easily send your message.
Now wherever you see the sharing menu with an option to compose a Messages message, then you should be able to remove any attachments and send the message to anyone you like. Handy, eh?