I would say follow, upvote, comment ... occasionally resteem.

The reason I say this is twofold. I have made significantly more on comments than I have on ANY of my posts. Also, a comment engages the author and encourages them to go and look what else you have written about.

The reason I say be sparing with resteems is that people come to your blog to know what you write and share. If you have a lot of resteems and little content, you will only encourage people to follow who you're resteeming. Also, you don't earn any money from the resteem, so you're better off writing something original.

If you really like something someone else has written, do some research on the topic and write something of your own about it. Mention who inspired you and even drop a link to their content to grow both of your followings!