Panos come out best between 11:00AM - 2:30PM, when the sun is at its highest. This, of course, if you want clear blue skies.
The next thing you want to do is set your camera settings manually starting with the brightest area. I shoot in Raw but you can shoot in JPG. Auto exposure tends to change the exposure of each image tile, and set your white balance depending on the day light (sun or clouds), 4:3 ratio. Images must be in 4:3 ratio and do not use auto camera settings and Auto exposure. I suggest ISO at 100, shutter speed above 1/250th, and an aperture at 5.6 to 8.0 if using a P4 Pro. Adjust the shutter speed to maintain the aperture I suggested. Litchi and AutoPilot have automated modes to do this, but if you do not have an autonomous flying app this can be accomplished manually. Angle the camera to 20 degrees for the first row and do a 360 spin while taking 12 images. The images must overlap. Rotate slowly. In essence, you’ll rotate, take a picture, rotate, take a picture, rotate. Next angle the camera to about -17 degrees downward and do another 360 spin while taking 7 images. The images must overlap. Rotate slowly. Do not angle the camera upward. Next step is to angle the camera down to about -53 degrees and shoot another 7 images. To complete the pano angle the gimbal all the way down to -90 degrees and take 2 pictures, basically take 1 picture and rotate and take another picture after the rotation.
I have both Autopilot and Litchi, but I have gotten better results with Autopilot. For some odd reason, sometimes Litchi does weird stuff when running Pano missions, in the middle of the mission the aircraft just hovers without finishing the mission. I had this happened to me couple of times working commercially.
If using AP or Litchi take the images at 3 rows starting at above 20° above the horizon with 8 images per row left to right. then move down 30° and repeat, accept the Nadir defaults 2 images facing 90° down.
Once you have all of the pictures, it is time to stitch them together in the computer. There are various programs out there that can do this. Hugin is a nice free image stitching software and GIMP is a Free image manipulation software with similar capabilities to Lightroom or Photoshop. Download both and install them in your computer. I'm pretty sure they have Windows versions, I use Mac.