This is not biblical, nor written in stone, these are some simple tips from me for making and running a simblr. Every simblr is different and that is part of what I love about it but I have had people ask me for advice, so here it is.

(Remember folks, this is subjective, what works for one may not be good for another)

1. Make your simblr a separate tumblr, not a “baby” blog under your main or personal tumblr. Why? So that you can follow people and have a dashboard full of sim goodness!
2. On the front page of your blog, have a little blurb about yourself and sims so when people stumble by, they get a sense of what your blog is about.
3. If you want people to interact with your simblr, enabled replies and asks in your blog settings.
4. Tag, tag and tag your posts some more. If you are doing a legacy/challenge/offering downloads/etc and you want people to be able to follow it, tag it with a unique tag. Then create a link on your main page. [ http://yoursimblr.tumblr.com/tagged/youruniquetag ] Using /chrono at the end of a link on tumblr for tags enables people to view your tagged posts oldest to youngest.
5. Try and keep it sim related as much as possible. Personal posts here and there are fine but if you have more personal/fandom/surveys than sim stuff you might lose simblr followers.
6. Follow other simblrs! Most simblrs follow back simblrs. Need a place to get started, here is my blogroll and my Follow Friday list.
7. Remember, it takes time to get rolling. It took me about six months to become part of the community. Half the posts on my first 30 pages have no notes. 
8. Post because you love what you are posting, not because you need or want notes and reblogs. You will be happier in the long run.
9. If you have anon messaging on, sooner or later you might get a critic type message, a complaint or worse, a hate message. My advice for hate messages? Do not post it publicly, do not even respond to it. Delete it. If it hurts too much, turn off anon. Simple as that.
10. Reach out to other simblrs, send a nice message, leave a nice reply. Who knows, you could make someone’s day or even a new friend.
11. There are certain tags that are a curtsy here in Simblr-verse. “saviorhide” and “nsfw”. Most simblrs use tumblr savior. So many people tag their text post or replies to replies posts as “saviorhide” and any post that has any type of nudity or adult themes with “nsfw”.
12. Common terms used in Simblr posts: wcif=where can I find. nsfw=not safe for work. wip=work in progress
13. A great screenshot makes simblr smile! Learn how to take and edit your screenshots. Sims for Sale has great resources here and the LoveofPixels has amazing tutorials here.
14. Keep the original/to reblogged posts ratio favoring originality. You will get more positive feedback by posting your own things/stories/screenshots (It is nice to reblog others now and then too, just not 80% of the time).
         The exception to this is if you are a “specialty simblr”, for example, you only post house design, custom content finds or hot sim guys, etc. ;)

To be continued, this is an ongoing guide. I will add to it when I get more inspiration or even advice from fellow simblrs. :)