1. Craigslist Accounts Or Mails
You can't post on one acount to 10+ cities cause Craigslist will automatically find your strange behaviour and ghost all your ads. I recommend 1 account or mail for 2,3 ads for safety.
2. IP Address
You can't also post a lot of ads using same ip addess. Change your ip every 5-10 posts, don't use public proxies because they don't work!
3. Post Delay
Posting ad one after another in 10-20 seconds also won't work. You have to post ads every 30 seconds to few minutes dependly how many craigslist accounts do u use or on which section do you post, what kind of tactic do you use in your ads.
4. Ad Headline And Body
You have to be aware that Craigslist ban some words and phrases that are inside some spammy ads, they way to find which one of words are in this blacklist is simply testing, testing and testing.
5. Links, Images
Basically you can't your domain over and over again for link or image. I won't post more then 10 ads using same domain for a link. Although it will still lately be burned, will last longer.
6. Section, City
Each section, even city have different rules. You won't have any success until you will start to test your ads and find the best way for yourself.
7. Unexpected Circumstances
Sometimes Craigslist is doing something in some sections, changing and no ads got throgh there, it happen often in job section in some cities. You can't do anything with it though ;p
So basically there are few rules you have to restrict to get listed in Craigslist. Of course it's vary to every section but I showed before some universal that should work in most cases. To remember better the informations, watch below video: