Hello, welcome to my first build I've made so please bare with me , I hope you enjoy it.
So its been a little bit since her release and i found neither ap or jungle to be extremely good on her, and through trials i have concluded the best way to play elise is hybrid.

So we are going to have my standard rune set up here for most of my AP champs. Your going to have your 3 Flat AP quints, 9 Magic pen. Marks, 9 AP/level Seals, and 9 AP/level Glyphs.

-The Quints are just for that beginning damage and to get you a little more kick with the scaling from masteries
-The magic pen marks are you standard AP rune so you can get more damage in overall throughout the game
-The AP per level seals are for more damage as you level throughout the game, plus overall you get more AP with per level runes than flat AP ones
-The Glyphs are for more or less the exact reason as the seals for overall more AP

I do a 21-0-9 build. You get the standard path for an AP on the offense tree, but with 3 on Mental Force and 3 on Blast. then you take the 4% into Attack Speed, because when you pop your w in spider form your going to speed up quite a bit, plus the extra 4%.

You get the 9 into utilities, for the bonus movement speed which allows you to roam faster, or get places faster, you get more mana for some more spammability, then the longer duration of Neutral Buffs. Unless your support you should always have this, This means longer baron, longer blue, or even longer red. Your taking your point in improved Flash so you get it 15 seconds faster. I can't recall how many times I've had my flash just in time to get a kill or to not get killed.

so yeah for items i suggest getting:
- ionian boots for the extra cool-down reduction so you can spam your abilities more often for offence or defence since most of Elise's spells have a long cd besides her q and ult
- malady for extra attack speed, AP, and magic resist lowering
-trinity, this is for overall sustainability, make sure to remember this item has an active which slows and does 300 damage, i forget this so much. This item gives us both spell vamp for in human form and spider form but also life steal for when we use w and charge an enemy down.
-Warmogs, well this item again is for overall sustainability since you will be focused down big time in most fights(it's hard not to notice a giant spider attacking you)
- deathcap, this is the standard AP item for most magic based champions since it gives you off the bat a decent chunk of AP and a nice 30 % boost to your AP as well

OK. So with this we go Q-W-E Then we max R-Q-W-E

R first because maxing it means you can summon more spiderlings, which means you can burst down someone faster, and take towers out quicker.

Q second, because it is your most damaging combo. if you can attack or poke your enemy with full hp then turn around and Q them in spider, it will do massive amounts of damage.

W third, because it is still a damaging ability but its not a burst enough to be wanted first. plus you wont be using that W on spider nearly as much with trinity and malady at hand.

E last, since its only for utility, and it does it's job well enough with 1 point, all adding to it does is reduce the cd and nothing else

OK. So generally speaking we are going to grab flash, and Ignite. you can switch up ignite for exhaust, it really depends upon your play style. But flash is a must, it allows you to catch up then E in spider form to close gaps and immediately q on someone.

In the beginning farming with elise is quite hard i'm not going to lie. Her auto attack has average range for a caster so you can get those back creeps fairly safely, but her attack is extremely weak, so you have to last hit as much as possible, also this is the part when you use your q in human form to harass the enemy from range,and with her w try to aim it away from minions and close to your enemy if trying to hit them so it can bypass the minions and chase the champion, it might take you a while to master but it's effective that way. in addition be careful yourself because you may never no what situations might happen.

So that was my first guide, I'm sorry if you don't like it or anything such as that. This build is still in construction and development so feel free to post a comment here don't forget to vote this build as well i want your opinion and don't care if it's positive or negative. I hope you enjoyed this guide and hope it was helpful, have a fun time inducing arachnophobia in your opponents.