If you are a manual curator I would love to hear how you are handling your curation. Here are some questions:

To be honest I just passed a benchmark of 5k steem, on my blogging account - which I see an achievement, but Can't really make a difference regarding curation. However, long ago I decided to join Curie curation team, and recently I was invited to OCD curation group (I guess the reputation follows :) ).

Should I base my upvotes solely on the quality of the posts and thereby support people who already know how to produce?

Ah that quality - and exceptional quality, these two words are so mystified on steem. To be honest, I don't like them - I like to curate interesting posts, something that radiates out of the mass production. The same thing is - photos don't always have to be made with the latest tech, but the composition and adding a bit of writer's soul to the post is what I'm looking for when curating. (I never had an expensive Camera - yet managed to get few rewards, but obviously, sometimes I really like to write :))

Should I assign some of the upvotes to people to encourage them to become great authors?

Another problem... The authors I liked and saw the potential in them were usually dropping non-effort posts, but whenever they but a bit of effort I would try to get them at least a bit higher reward than they usually get - just trying to get them to realize that it's okay to spend more than 10-15 minutes per post. So my answer is positive to this question, but carefully choosing which posts you curate and not too often, then people become lazy, and don't tend to change anything.

How much should I direct towards diversification? For example, to make the place more interesting by upvoting authors from many countries (that may follow ethical rules that would be called unethical elsewhere)?

So, if it doesn't take you too much time and effort to filter authors through a country of origin and language, that is a nice way to distribute steem all over the world - and I really like of the charity efforts done on the blockchain.Another thing we tried to do with the @crowdmind project, to try and unite as many countries as possible under one umbrella - and diversify curation of crowdsourcing activities, but usually all countries have their teams and try to stick together and they are not willing to change anything (sticking to tradition :) ).

And that is a long read, sorry about that :) I'm so happy that.

P.S.
Your note at the end just shows what a great person you are! It's a pleasure sharing the network and words with you.

Cheers!