Asked on a forum today: "When resizing your photos for print, do you use the Crop Tool or the Image Size function?"
Cropping is unnecessary if you've composed your image exactly right in camera, AND you've chosen a 2:3 print size that matches your camera's sensor shape - eg 6x4, 6x9, 8x12, etc. But it's pretty rare that both of those factors align for you, so it's common to have to crop for print, either for composition, or print shape, or both.
There are several schools of thought on this ...
1. Don't crop, don't resize, don't do anything
This can apply if you upload to your lab via ROES or similar, which allows you to choose the crop while uploading. This is undoubtedly the easiest way, but you can't accurately sharpen your images if you do it this way; so if sharpening is important to you, avoid this method. (The case for resampling)
Obviously, this method requires neither the Crop Tool nor the Image Size dialog.
Here's a pretty severe example of focus falling where you don't want it:
But it's a cute photo, right? It would be nice to make it just good enough to share with friends on Facebook, at least. Well, it's possible to create a bit of "false focus" by sharpening the subject and blurring everything else. It won't be perfect, but it will help a little.
It's not unusual to witness confusion between these two options:
They're right next to each other in Photoshop's "Edit" menu, and they both involve changing your image from one colour space to another (eg Adobe RGB to sRGB); but they're vastly different functions, and definitely not interchangeable.
Let's be clear up front - if you need an image to go from one colour profile to another, it's 99.99999999999% likely that Convert to profile is the one you need. Assigning a profile is so darn rare that I can't think of a single reason why a photographer would need to do it in their day-to-day workflow.
Even if you read no further, this is the important message - Converting is your friend; assigning is almost always your foe.