you absolutely must build military units all the time. start thinking to yourself, "can I afford to not build warriors for the 13 turns it takes to build this grainery?" the answer is always no. Also, your first city needs to be placed on a hill. that immediately gives you a 25% better chance of not losing the game. its placement needs to be touching either gold, incense, dye, or some other high cash tile. Also, "No settlers" option enabled is gonna give you some time and encourage you to have open borders with people. I know when I play with settlers and some one asks me for open borders, then first thing that comes to mind is, "your just trying to get settlers behind my lines to that small patch of land I have no use for!" and they always do!
but seriously, you gotta be military minded, and flexible to accept things you may not be used to, like RoK with elves, or skipping God-King for city States, or giving tribute so some one doesnt attack you.