What can I do about my 15 month old's temper tantrums?

My 15 month old must be starting the terrible two's early. I try my best to not put him in situations where he's not too tired or hungry, but he's beginning to get quite stubborn and vocal about not getting his way. I am kinda at a loss about what to do about his tantrums. I have been letting him tantrum and then comforting him after he calms down. Is that OK? What can I do to stop them? They seem to be getting worse. Today has been a tough day for us. I kinda feel like crying as well. We did take a nice walk that he enjoyed, but he had a major meltdown afterwards. :(