Some basics:
Keep in mind that the idea of the perfect landing is to have both wings stall exactly as the landing gear touches the runway. That flaps are not a speed control but are used to increase the angle of descent. When flaps are applied, they require the pilot to do one of two things, lower the nose to maintain the current indicated airspeed and there by give up altitude or increase power to maintain the current altitude and airspeed. An Airport traffic pattern was and still is made up of 5 elements, (1.Pattern Entry, (2.Down-wind, (3.base leg and (4.final approach, (5. Touch Down and roll out. There are many ways to enter the airport pattern the idea is to arrive at the traffic pattern airspeed, that was 250 indicated for most fighter airfields in WWII. The down –wind is parallel to the intended runway of landing, flying in the opposite direction of the intended landing heading.
For landing any aircraft , indicated airspeed is critical. Airspeed during the entire approach is the most important element. To slow you may stall and crash, to fast and the aircraft will float down the runway or fishtail after landing.
You need to start to slow the aircraft down for landing prior to entering down wind for your landing runway. You control airspeed with the stick, raise the nose, lowers the airspeed, lower the nose raises the airspeed. You control altitude with power, you want to go up you add power, you want to go down, you reduce power.
The P51 will allow you to lower the first notch of flaps (combat flaps) at 300 MPH indicated, with the power reduced or off you hold straight and level and allow speed to bleed off, at 300 you put out one notch of flaps. At 250 you put in a second notch of flaps, power off, straight and level aircraft is slowing for pattern entry to land on the NE runway you are turing on to a SW heading for a Left Down-wind leg.
On Downwind about 1500 feet AGL as your airspeed continues to slows to below 175 you can extend your gear and lower your nose to maintain an approach speed of 150, you are descending now and put in the third notch of flaps while extending your left down-wind for your turn onto your left base leg (90 degree turn to the left) . You are descending now with the airspeed slowing to 125 use your stick and power to maintain 125 while descending to about 800 ft AGL. Turning onto final approach about 1.5 miles from the end of the runway.
Time for the Fourth and perhaps fifth notch of flaps. Allow speed to slow to about 110, but not less then 100. As you approach the end of the runway, and begin your transition to level flight just above the runway, then hold it off as the aircraft starts to settle, hold it off, you will end up in a slightly nose high attitude with the airspeed slowing and approaching stall, keep wings level, you should be very close to a full stall, lots of shaking and stall warning horn.
Don’t forget the rudder. Standard props need right rudder, but use what ever rudder is needed to hold center line. As the aircraft slows even more the rudder will become ineffective.