Unfortunately, killing Lynels has become boring for me, unless I make it intentionally hard by not using really powerful weapons, stasis or bow shots to the face. My inventory is fully maxed out, and I'm carrying around 5 savage Lynel clubs (all gold, with damage from 78 up to 108), 5 savage Lynel swords (with damage from 58 up to 99), and then a lot of royal broadswords and royal claymores. The amount of damage I can do very easily if I want to is ridiculous. If you are simply farming them, here's what I do, and it works so well that you usually can beat them before they ever even make a single attack move against you...
1. approach either gliding in or running straight at them
2. if gliding in, when close enough, just start pelting him in the face with whatever arrows you want. The slow-mo allows you to get at least 4 shots in, if not 5 or 6. If running in, just have your bow ready to go as soon as he rears back and growels to do his huge fire-blast move. As soon as he rears back, shoot him in the face with an arrow to stun him.
3. now that he's stunned, run up and attack from the front left or right with a single blow or maybe two. You should now see the MOUNT signal, so mount him.
4. at this point, take out your most powerful weapon and whack him 5 times
5. right after the 5th hit, he'll buck you off, but when he does, draw your bow again and shoot him in the back of the head. This will do major damage, but won't stun him again.
6. Start running at him again as soon as you can, and then stasis him when you're really close.
7. As soon as you can, pull out a two-handed weapon and start spin-attacking him. By this time, Urbosa's fury should be ready, but keep spinning until you realize he's about to either try to run off or attack.
8. At the point he's about to get away from your spin attack, use Urbosa's fury on him. This - by now - is very likely to finish him off. If not, you can still run up to him again while he's being electrocuted and start spin-attacking him again. That WILL finish him off.
If you do not have Urbosa's fury ... or if it's run out and recharging at that time ... just let him run off after the spin attack, and when he comes back at you, either dodge or block the attack and then stasis him again. Go attack, which wills stun him, and mount him. Again, use your most powerful weapon while mounted, get bucked off, and keep repeating the cycle until he's dead.
Lynels - unlike Bokoblins, Moblins or Lizalfos - are all about timing, and patterns. As soon as you are familiar enough with how they operate, they are simple to beat. The fact that you're one-on-one with them means you have nothing else to worry about, which in and of itself makes the task a lot easier. I guess that's the trade-off though for them having so much HP ... they are predictable, and it's more about you making a mistake, not them over-powering you or catching you off guard.
on a final note ... to me, the hardest block to make is with the club. But, again, it's timing, and not THAT hard to get used to.