There are many ways to do thisith your image in Photoshop. Here is a quick method. Apologies for the screengrabs being rushed, it's after midnight and I need my bed soon.

Basically you use the selection tools (round marquee, lasso etc.) to select the areas that tears will occupy. You can feather the selections if you want, I didn't here. Holding down SHIFT when adding selections will retain all your selections.

Ctrl+C to copy your selections. Then Layer>New layer to create a new blank layer. Now with the new layer selected, Ctrl+V to paste your selections into the new blank layer.

With the new layer still selected, click the FX tab at the bottom of the layers palette and choose Bevel & Emboss. Now play with the settings to get a raised look to your tears. Pay attention to the ligting angle so it matches the lighting angles in your image. When you have it looking reasonably to your liking, assign the changes.

Now play with the opacity again. You can use the Dodge tool (or paintbrush set to white and low opacity) to create highlights on the tears, or make the tears look like other "body fluids" with the Saturation (Ctrl+U) Tool and bumping the Lightness up.