Playing laning phase is pretty cancer lol, you have to do alot of poking with your autos to get them down to a good hp level when you can full combo them with ease. The best way to poke them with you autos is to weave in and out of the bushes after each auto. That way after every auto you do you will automatically cancel the minion agro, wich is a big part of her play style. Elise top is one of the most agressive champion there is, you cant play passively as Elise top unless you are behind or vs a champ that over powers you. As elise top you want to crush your laning phase to the point were they would need to send atleast 2 to stop you.

Mid game is simple you roam for picks, split push and get objectives like dragons and herald.

Late game is all about picks and jumping on the back line. what you want to do is get sweeper and roam their jungle and try to get picks, then when you do you can either try and push for a 4v5 or bait baron. as elise what you want to do is to try and assasinate the back line, if you cant do that then you can peel for your ADC.

Elises full combo is, Humain form-W E Q Spider form-Q W auto auto auto... then E away if needed.

If they are far away you, Spider form-E on them Humain form-W E Q walk close to them then Spider form-Q W.

If you have a hard time hiting your Humain form E you can use your Hextech Gunblade to slow them down to be able to him your Humain form E easier.