Dear @beautiful12, the effective ways you listed in which one can promote steem are perfect and I totally agree with you on the below point of yours;

Placing fences in shopping centers, in the main avenues and highways of my country. That they be fences that draw the attention of the population.

Shopping center is where more than thousands of people come in to purchase things for their daily needs. Putting a fence around can attract eyes and as such; people will show interest in knowing what steemit is all about.

Good to read through your article, success!