First initialize an project

$ ng new project-name --createApplication=false

If you want to use scss for your styling, just use the style flag and point it to scss

$ ng new project-name --createApplication=false --style=scss

Create your angular library

$ cd project-name
$ ng generate library library-name

If you want to use your own prefix to replace lib that Angular CLI uses by default, use prefix flag and point it to new prefix-name

$ cd project-name
$ ng generate library library-name --prefix=prefix-name

Warning: You can't remove the service even though it is no use in your library, please don't forget to export your LibraryComponent in your LibraryModule

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { LibraryComponent } from './library-name.component';
import { LibraryService } from './library-name.service';

@NgModule({
  declarations: [LibraryComponent],
  imports: [
    CommonModule
  ],
  providers: [LibraryService],
  exports: [LibraryComponent]
})
export class LibraryModule { }

Test your library first before publishing it to npm

# Build your library for local testing
$ ng build library-name

# Create a angular project to test your library
$ ng generate application project-name-test

Test your library in app module

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { LibraryModule } from 'library-name';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    LibraryModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

Usage in your app html

<lib-library-name />

If you have defined your own prefix, try the following

<prefix-name-library-name />