The important things to remember during and just after a sighting of an anomalous phenomenon:
Shoot video if you can. Don’t zoom in too much
Include reference objects in the frame of your video.
If shooting video, note the time, date, and location out loud.
Pull over and get out to observe if you can do so safely.
If indoors, go outside if you can do so quickly.
Observe the object for as long as possible.
After the sighting, make sketches with notes ASAP.
Get contact info for other witnesses, don’t compare notes.
Go to reportaufo.org, fill in the simple form, and upload your sketch.