Riven is an early game dominant champion who can take over the lane through short trades. Try not to trade with her unless you can match her trading potential.
Riven will often play hyper-aggressive and try to outplay you with her Q. If possible, try to bait out her main abilities and then re-engage when she has cooldowns. This is your best bet when laning against a Riven.
Keep the minion wave frozen near your Tower. If you are playing close to your Tower, her all-in potential is limited as the Tower will protect you and she will not be able to look for frequent trades.
Riven will be looking to split push when no team fights are occurring. Make sure somebody who can contest her is sent to stop her from pushing. Avoid fighting her during the mid-game though unless you’re stronger.
Teamfights will be difficult for Riven as she is prone to CC, disengage and gets kited by champions easily. To make team fighting easier, she will probably flank or Flash in to engage. Ward to the side when sieging an objective to spot her before she gets the chance to engage.
Riven is quite good at picking off champions when they’re too far forward or alone. Don’t let her pick someone off by staying in line with each other. Do not group too closely as it may allow her to get a 5 person W stun.
Riven can easily 1v1 any champion at level 3 if she is in a favourable matchup. Do not overextend to reduce her chances of killing you.
When Riven unlocks her Ultimate R, her all-in potential increases dramatically. Make sure you disengage if she tries to fight you unless you have an advantage.
Once Riven has completed two or three items, she becomes very strong and will be able to take down any squishy champion that is not a tank. If you see her running towards you- just back away.