Caitlyn
In lane I recommend poking your Opponent at every good opportunity with Headshot or normal Autos as it helps gain Lane priority and reduces the chances of them all outing you. Piltover Peacemaker can be used as poke but remember that it loses damage afer hitting a target unless they are in a Yordle Snap Trap and for gods sake, watch your Mana.

Use 90 Caliber Net (E) to disengage if you feel threatened or need to fallback. Remember if they walk up to all in 90 Caliber Net Piltover Peacemaker (E Q) is a nasty combo to not only damage them but to escape and deter their all in.

Yordle Snap Trap is a very useful laning phase tool, as by placing traps between you and your opponent it creates a funnel they must use to get too you. Placing traps in the wave is also good as minions may cover them or when they walk up for CS they may step in one granting a free Headshot

Jhin
In lane I recommend always poking with Whisper 4th shot and Dancing Grenade 4th bounce by bouncing it off the casters and melees onto them when they walk up to CS.

From my experience so far Jhin does a lot of damage early (pre first buy & after) which mid laners dont expect from you so by using that to your advantage if they attempt an all in (before their first buy) just fight them back to their tower unless their wave is massive but generally you can be really punishing especially with Whisper 4th shot when they are low hp.