If you don't have much steem power you need to make a different strategy while curating.
You should vote the post you think will be a big hit. And you need to vote early. The first 1% get most of the rewards. But if you vote too early you don't get anything (first 5 minutes). If you vote after 30 minutes you get 100% of your vote, and if you vote at 15 minutes you get 50%.
For very good posts it is better to vote earlier than 30 minutes because you get for example 30% from a bigger reward.
I just got a big hit today, I only have 390 STEEM and I just received 0.5 STEEM for a vote:
Curation reward of 0.489 STEEM POWER for dollarvigilante/the-dollar-vigilante-is-now-on-steemit
Thank you