I have something that will help you in this first section if you care to read it. If not it'no biggie, you can just skip to the second part if you want. I'm just putting it out there to help out:
Attack-Animation Canceling
I suggest going into a custom with Jax (or any auto-orientated champion you want to practice this on, including adcs) and go to scuttle, as it runs away which is good for what I'm about to suggest.
You go to this scuttle and auto it, but don't let the entire auto animation complete and instead click to move during the animation. The trick to this is that if you click too early, the attack is "canceled" and the damage isn't applied, but if you click just after the damage is dealt (but the ending attack animation is still in process) you can shave off some crucial time between autos in order to keep up with someone who's running away. It's essential animation canceling (think: Riven) only for autos rather than abilities.This method works for any sort of displacement, but the "move" function tends to be the most common method unless you're...well, Riven (and a few others). Here's a little clip to show you:
http://plays.tv/video/5948bd0288a5181646/for-that-one-dude-on-the-boards
I'm not perfect at it but at least it gives some visual example. Also, each champion's attack animation is different and so some champions can shave off more time from this method than others. I'm more familiar with Yi than Jax, but I'm sure Jax is able to do this attack-animation cancel pretty efficiently as well.
And don't worry about reflexes you grandpa, it's really more about muscle memory and you'll find it's pretty easy after doing it for a couple minutes.
As for his meditate, if you think you'll win coming as he's coming out of it then by all means continue autoing him. Autoing will tend to eliminate the healing effects at early levels and gives you time reset your cooldowns. When he comes out of it, then you make use of your abilities. The problem is that you used your W while he was taking reduced damage, if you had done so as he came out of it then the full damage would've likely killed him.
It's also important to note the Yi is a great champion for lower-elos (arguably one of the best, I'd say top 5). This is because of several reasons:
- jungle pressure is a relatively unknown thing in lower-elo junglers
- Lower elos tend to not run very cc-orientated team comps
- lower elos tend to not know how to effectively use cc on key members of the enemy's team
- lower elos don't know how to close out games, and they often stretch to much longer times than they should (which allows Yi to reach late game in which the only way to shut him down is...cc, which is a problem as you can probably tell)
You can see that he's really only efficient in lower elos as his win-rate steadily drops as the elo rises. He finally drops below a 50% win rate in plat+ elo and even rocking a 48% win ratio in Diamond+
I hope some of this helped you my dude, I've played quite a lot of Yi in my time so I'd hope I know a bit about him. I actually have climbed from bronze 4 - gold 5 with pretty much Zac + Yi twice, and have abused Yi several times while playing with lower-elo friends when the average team mmr drops. I'm a pretty dirty dude when it comes to the jungle >-<