Car door out of alignment

So my door is out of alignment so it doesn't close from the outside unless I grab one of the ribs on my side skirts to lift the door into place and this can still take several tries I've tried adjusting the striker and latching mechanism but it is still getting progressively worse how can I fix this with out taking it to a shop? I have years of experience working on cars especially transmissions as kind of an apprentice at my dad's shop but have never run across this before and my father is no longer around to tell me. So what should I do?