I'm absolutely rubbish with Kayle.
Tell me your secrets Stocking.
1. doran's + 2 health pots for sustain
2. rush stinger, then lich bane
3. get tooth, then rabbadon's deathcap
against melee, position yourself between the minions in the middle and their tower, ward the bush closest to you and poke the melee if he tries to get close. kayle is very, very good at running away with her W and if you ward correctly you should never get ganked by their jungler. against range, hide behind minions and poke. against champions like annie, ahri, heimerdinger, and ashe, you'll be asploded in like 2 seconds if you try to go balls deep.
beg your jungler for blue buff when you can, the self heal is super expensive but if you get blue you can use it on cooldown and it's basically infinite sustain.
max out E to make it easy to mass-farm CS and poke, and then your Q. if you have lich bane and you Q, your ranged autoattack does a huge amount of damage and gives you like insane burst. use your W or ult on yourself 2 seconds after and you'll hit them for another chunk. i killed a Jinx that was 9/0/1 in ~2 seconds doing that once i had my build together. even without the lichbane burst, your autoattacks can mow down an entire team in seconds if you dont get focused, so you'll be focused like every team fight.
Be not level 30. 
i think its probably worse. 90% of the people I queue into are smurfs and half the time i'm forced to jungle because literally no one on my team wants to jungle. jungling with kayle is a nightmare especially when you're jungling against udyr and he pushes a hard counter jungle.
unrelated but am i the only one who is totally gay for leona, i mean
damn she fine
Poll