Sniping the whales isn't as profitable as most people think it is. It's a competitive game. I'll let you in on a secret. Go for the second tier user, not the highest earners. The vote mass to front run can be much more favourably distributed. Also, if you find a post you think might become popular, give it a big upvote and resteem it to put more eyes on it!
I suggest anyone who doubts my words go and take a deep dive into the curation rewards on SteemWorld.
Actually on my trail votes I have fairly tight limits and avoid voting on people with too many votes or rewards automatically. Can't vote for everyone and the people with smaller payouts will notice it more.
I'll still manually curate whatever I lile regardless.