If you have only a small amount of steem you need a different strategy when upvote. You should upvote only some really good articles, and you should vote when it has only 1-4 votes. Also you should only vote for posts you think will get a ton of votes.
Read this guide: https://steem.io/getinvolved/paid-to-curate/
But the best way to earn STEEM if you make good original content.
I hope it helps.
Thanks for the hint. But - stupid question - where is the upvote button? Take care, juergen
Under the comment you see an arrow pointing up, left from $0.00 . If you click on it you upvote the coment.
Got it. Thx again. ;-) That was quick @spiz0r
One more quick tip. You can check your account at steemd.com with more detail:
https://steemd.com/@juergen
Here you also can see "voting power" so you can check if it goes to low.
+1 If you have really few steam power, it might be a good idea to vote to your own comment. It might help in the long run.