If I am developing a rather simple Spring Boot console-based application, I am unsure about the placement of the main execution code. Should I place it in the          
        
You should have a standard loader:
@SpringBootApplication
public class MyDemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(MyDemoApplication.class, args);
    }
}
and implement a CommandLineRunner interface with @Component annotation
    @Component
    public class MyRunner implements CommandLineRunner {
       @Override    
       public void run(String... args) throws Exception {
      }
   }
@EnableAutoConfiguration will do the usual SpringBoot magic.
UPDATE:
As @jeton suggests the laters Springboot implements a straight:
spring.main.web-environment=false
spring.main.banner-mode=off
See docs at 72.2