DEFINITELY DO:

Have a neat, classy theme installed.
Having a good theme is essential if you want people to enjoy the experience of your blog. Enable endless scrolling and definitely disable photo captions. The most compatible themes for photography-based blogs tend to be the ones with 3-4 columns where photo captions aren’t visible.
I have made a list of amazing theme-makers here.

Make and reblog promos!
When you get to about 1,000+ followers, start to do small promos on your blog. Usually “First 5 to reblog, must be following {you}” will reach. When you get to 2,000+, you can do “First 10”s pretty easily, and sometimes a bit more. When you reach 3k and 4k, “First 20”s should reach. (Etc.) Make your promos for reasonable amounts, and try to switch up the rewards! Also, make sure to always actually follow through with your promotions. Don’t only choose your friends to win them, and definitely NEVER just copy and paste the notes; If your followers are willing to reblog your promo, at least have the decentcy to do your best to get them followers. Reblogging promos is a very important concept as well, because your blog won’t get noticed without them. Remember, EVERY SINGLE FOLLOWER COUNTS, especially at the beginning! Try not to reblog too many at once (and if you do, delete them quickly!) and never bother the person hosting the promo to pick you.
Please be aware that engaging in promotions is against tumblr policy and can result in the deactivation or termination of your blog. 

Have a clean and unique URL!
Having a creative, different, and clean URL is key to getting your blog noticed without people having to click a thing. I suggest staying far away from numbers (“wishonastar456”) and names (“jessicarawrrr”). Long URLs are also annoying, and be hesitant to use too many dashes (“h-o-t-d-a-y-s-b-e-a-c-h-b-a-b-e-s”). Make sure it fits your blog, as well! If you have a skate/surf blog, make sure your url reflects it! Lastly, really spend a lot of time trying to make your URL stand out. URLs like “oceanwaves”, “sandysun”, “beachblondes”, etc. are nice and descriptive, but I think I know five or six blogs with variations of each.

Keep it classy at all times.
BE A NICE, CLASSY PERSON. Sending hate or responding to normal questions with ridiculous attitude is a waste of time and proves that you don’t deserve followers. If you get a lot of hate, seriously consider removing the anon option. Having your followers like you is not only a compliment, but also a wonderful, useful tool. It requires time, but it’s so worth it, and my beautiful followers repay me - if I’m close to a goal, so many of them offer to help me. APPRECIATING EVERY FOLLOWER IS KEY TO RUNNING A SUCCESSFUL, LOVED BLOG.

READ EVERY BLOG’S FAQ BEFORE ASKING QUESTIONS!
The FAQ is there for a reason! People with many thousands of followers get hundreds of messages a day. Reading the FAQ is polite and mannerly, and if you want people to give you the respect of reading it, you better do so yourself. If someone’s FAQ says “No, I won’t promo you”, then don’t ask for a damn promo. If someone’s FAQ clearly says they won’t vote for blogs in contests, don’t ask! Not reading someone’s FAQ is the easiest and fastest way to get blocked on tumblr, because it takes less than a minute to read and it’s meant to save the blog-owner time and effort. Respect that.

Stay true to the theme of your blog.
I consider all blogs that don’t stick to a theme as “personal” blogs. If you are a beach blog, please don’t post gifs and personal posts and unrelated photographs. It doesn’t look good and it destroys the coherency of your blog. You can feel free, though, to mix somewhat-relatable themes - surf/skate, surf/summer, summer/boho, color/summer, etc.

Update frequently!
Reblog a lot every day. If you can’t handle that commitment, create a long queue and have that constantly running. (BUT PLEASE DON’T ADD “QUEUED PHOTO” UNDER EVERY QUEUED PHOTO - that’s annoying and unnecessary!) People unfollow blogs after 1-2 days of inactivity, and you are sure to lose large chunks of followers if you go any longer than that without posting. Tumblr can be quite competitive.

Lastly, be happy with the way your tumblr is, and remember that no one’s opinion about your blog is as important as your own.
This is self-explanatory. <3


DEFINITELY DON’T:

Never, ever self-promote. I can’t stress this enough.
DO NOT SELF-PROMOTE ON EVERY PHOTO YOU REBLOG. It pisses so many people off and you’ll lose significantly more followers than you’ll gain. I personally will unfollow you. Not only is it rude, but I feel like it borders on fucked up because the photos aren’t your property. Don’t self promote in someone’s ask box, either, unless someone explicitly says that it’s okay. I never post any self-promotions that get put in my ask, and I generally unfollow/block the person if it’s especially annoying.

Avoid getting unhealthily obsessed with gaining followers.
Yes, everyone loves getting followers, but it shouldn’t become your life and it should never come before blogging what you like to reblog. “Blog to express, not to impress.” Obsessing over how many people follow and unfollow you will only lead to misery and likely degrade the quality of your blog.

Don’t clutter everyone’s dashboards.
Delete text posts after 10-30 minutes, and make a habit of going through your archive to make sure it’s neat every once in a while. Similarly, don’t publish all your messages! Respond privately to compliments (it’s not classy to publish it/brag), delete all hate before even answering it, and only keep anonymously asked questions up for a short period of time. Furthermore, I don’t recommend filling up dashboards with voting spam. It’s annoying, and it’s a well-known fact that polls are trivial popularity contests, anyway.

DO NOT BE AN ASSHOLE.
Never be unappreciative, never spout your mouth cursing (a lot of girls on tumblr are young, so try to keep your class), never cause drama with other blogs, and NEVER post messages that make you look like an asshole! Even if someone is annoying you, there’s NO need to be a bitch or embarass anyone publicly. Why not just report them privately? If you’re nice and loving to your followers, and you prove to them that you are a caring person, it will pay off, I guarantee you. :)