Damn you beat me with describing the techniques. I only want to add, it is really important to use both eyes and ears when looping and trying to loop perfect. You see the wavecycles (repeated audio) with eyes, and similar looking will loop smoothest when the loop points are set properly and at “the same” crossings. Also you have to dig in deep with your ears when it comes to timbre variations, at which places the sound sounds sameish, and place loop points (with zoom/eyes) in those sections.
Ping-Pong is always only a second choice for me, it is unavoidable to have at least very slight clicks in the loop whatever you do. Unless you place the markers at (short) silence sections. Ofter the clicks will drown in the mix though.
I wish there was better x-fading for looping purposes. One where you would first select your loop points, and have them preserved. And then when timbre modulation makes the loop sound clumsy (but otherwise looped alright) you’d select a range around the loop start, and have the corresponding range around the loop end faded in and out smoothly around the selection, the loop start point being the maximum fade-in point.