As lissandra, Their level 6 is incredibly strong, and their Jungler will gank them when they hit 6. Make sure you ward the river to spot the Jungler early.

Post 6, push the minion wave and walk backwards so they cannot trade with you or press R on you.

Stand outside of the minion wave at all times. It will force them to choose between pushing and poking you.

Focus on just farming and poking and harassing the enemy. You’re not very strong early on. As lissandra, Their level 6 is incredibly strong, and their Jungler will gank them when they hit 6. Make sure to keep the river to spot the Jungler early. Post 6, push the minion wave and walk backwards so they can't trade with you or press R on you. Stand outside the minion wave at any time. He will force them to choose between pushing and poking you. Focus on just farming and poking and harassing the enemy. You're not very early.