It's extremely simple to do once you've done it once, here's a quick rundown of how I do it (can land with high accuracy)
You're gonna want to "practice" by doing hops (like how SpaceX is doing it :))
Make sure that the craft has around 2200 Delta V in it (the craft shouldn't be too heavy)
Launch to an apoapsis of around 20k
A few seconds before you reach apoapsis you retract all the flaps, make sure that you have set them to inverted in the VAB as they retract the wrong way if you don't. If you don't retract all the body flaps before doing your flip maneuver it'll start spinning out of control.
Glide it down while controlling your landing spot using the WASD keys with all the flaps still retracted.
At around 1-2k click the retrograde button on your nav-ball and ignite your engines.
Once the craft has completed it's belly flop you can extend all the flaps to their normal position again.
Simply touch down.