Save Paper
Ink, toner, and paper costs continue to go up. PDF files create universally viewable documents that save paper now, save time searching through file cabinets, save floor space into the future.
Mark Them Up
The Preview.app, standard in OS X, is the default app for working with image files and pdf documents.
Annotation Tools in Preview.app
The Preview.app includes annotation tools that go beyond simple highlight, underline, and strike-through. Markup options include arrows, ovals, rectangles, text overlay, embedded notes and links, with color, line width, and full font options.
Combine and Merge PDF Files
To combine multiple pdf files, open the drawer of the first, and drop additional pdf pages and images into the box of the original. Do not just add them to the drawer, drop them right on top of the box. Then print the new creation to pdf.
Shrink PDF Files
Open a pdf file, then File-> Save As.. and use the quartz filter to shrink file sizes for PDF documents with many images on them.
Missing
The ability to perform two common tasks is missing from these built in tools. Freehand sketching, and placement and resizing of images directly in the document. Formulate Pro by Andrew de los Reyes is an extraordinary small light app that accomplishes these two tasks almost perfectly.
Formulate Pro to the rescue.
After installing, fire up Formulate Pro and drag any pdf file to the Formulate Pro icon on the dock. Then use the tool box item with the squiggly circles to do a free hand sketch right on the PDF (there is no undo option at this time, that would make it perfect).
To add images, choose File->Place Image.. from the Formulate Pro menu. Then select an image to layover the pdf page. After the image is added to the page, click the Arrow Toolbar icon in the formulate pro toolbox to move and re-size. This is an overlay, so text is not re-wrapped or anything fancy like that.
Formulate Pro Toolbox
Formulate Pro doesn't do much. What it does is EXACTLY FILL a couple of needs missing in the default Preview app.