Don't:

1. Write in caps lock.

Emphasis can be made even when you're not typing like you're angry. Rearranging the title or using different words can make the title just as eye-catching. 

2. Use your plot

People don't need to know what the story is about just based on the title- that's what the description is for. You can use some parts of your plot, like an item, but you don't need to put in the whole storyline. 

Example: I hate you but I fell in love with you    OR    I'm 16 but I'm getting married     OR    It's a secret, but I'm in love with a gangster

*Note: I made those titles up, I'm not pointing fingers, okay? And yes, those are titles mostly for 'you' fics, since they're the more common ones.

3. Put the whole "Sequel to..." 

Sure, it's informative, and people will know it's not the first story. However, you can write that as part of the foreword... and maybe even the description. 

4. Type in alternate capitals... or with too much "cute font" (whatever you call it)

Like this: I hAtE HiM              OR             Í  ðØñτ k∩öw

*Note: I don't see much of these nowadays, which is good, so don't start... I think it's good for graphics shops though...

5. Have too long of a title

It may sound and look catchy, but readers will end up forgetting what the title is after they start reading. If they didn't subscribe yet but their computer shut down (it can happen), they'll have a hard time looking for it.

Do:

1. Make a catchy title

Steer clear from titles that you see all the time. Browse at the titles and try not to make similar ones. It helps to use different words, but use vocabulary words sparingly... People will get intimidated at the sheer depth of the vocabulary.

2. Use a keyword

You can use a keyword from your story, something that represents the theme or plot of your story, as a title. It shouldn't give too much away, but leave readers wondering what will happen.

3. Write with proper capitalization

Titles are usually capitalized per word, with the exception of the prepositions, articles, and conjunctions... unless they're the first word.

Articles are the words "A," "An," and "The." 

Conjunctions include "And," "Or," and "But."

Prepositions include "From," "By," "Of," and "On." 

You also capitalize the first word after a colon ( : ), and hypenated words (High-Quality).

The word "I" is always capitalized.

4. Keep readers hanging

Titles are one of the first things readers see, so treat it like you're making an advertisement. What things make you click the title? What things turn you off?

I'll add more when I think of them. More to come~