A hole in the wall, literally. I spawned on the shore with a fairly steep set of hills around me, a small ravine of sorts running partway up. Near the top of the ravine I turned to the vertical face of the hill and dug in. Expanded it quite a lot over the next days. A proper door, a back door added after some creepers decided my front door was a great place to take a smoke break, ladder to the top where I left the trees in place (though I made the other side of the hill as sharp a drop so things couldn't climb onto my roof), ladder down to my mines, a greenhouse/balcony with flowers overlooking the sea, a tunnel downwards at a 45 degree angle so I could get to the shore (where my farm was) in peace, a bridge across the ravine, just outside my door. I remember being amazed that the dirt bridge was slowly populating with grass from the edges in!