How to Print a PDF File or Image from an iPhone

Problem: You would like to print a PDF file or Image from your iPhone, but you don't have an AirPrint compatible printer.

Solution: Use your Mac to print documents with the help of Dropbox and Automator.

What you will need:
1) A Mac connected to a printer (via USB, wifi, wired network)
2) Dropbox app installed on both your Mac and iPhone
3) Automator software (comes with Mac OS X)

On your Mac,
1) Create a folder in your Dropbox folder (give it a name such as "To Print"),
2) Launch Automator,
3) Create a new Automator workflow with File > New
4) When prompted, select Folder Action

5) Click on the "Choose folder" menu by the"Folder Action receives files and folders added to" label,

6) Choose the "Other..." menu item,

7) Select the Dropbox folder that you created in Step 1,

8) Add the Print Images workflow action to your workflow,

9) Check the Scale to Fit, select the desired Orientation (e.g., portrait), and the printer if you have more than one printer connected to your Mac, 

10) You can optionally add a Move Finder Items to Trash workflow action to delete the file after it's printed,

10) Save the Automator workflow (this automatically enables this workflow).

At this point, any PDF or Image placed in the "To Print" folder will be printed to the selected or default printer.

To print a PDF document in an email attachment from your iPhone,

1) Tap on the attachment (PDF file) in Mail app,

2) Tap on the Share toolbar icon (box with an arrow),

3) Select "Open in Dropbox",

4) Under the Save Location, tap on folder icon,

5) Navigate to the "To Print" folder that your created in Step 1 in the above instructions,

6) Tap on Choose,

7) Tap on Save.

To print a picture from your iPhone's camera roll,

1) Launch Dropbox,

2) Navigate to the "To Print" folder that your created in Step 1 in the above instructions,

3) Tap on the three dots on the top toolbar,

4) Tap on + Upload,

5) Select the image(s) you want to print.