staying in lane with no sustain champ

Riven's absurd kit is balanced by the fact that she has abysmal health regeneration and is very susceptible to poke. I would recommend not picking her into poke champions, or, simply try to force trades all the time. Riven usually trades well unless its a . Knowing when to use her shield helps as well

Use your shield as pseudo-sustain. If that is insufficient, consider refillable pots.

Also the new refillable pots could really help against pokey champions...against super safe poke it may not be the best idea to play Riven.