Cannot make bootable USB installer of Mojave 10.14.1

The 10.14.1 is an update, not a full installer.

Bootable USB Installers for OS X Mavericks, Yosemite, El Capitan, and Sierra

First, review this introductory article: Create a bootable installer for macOS. Second, read this How To outline for creating a bootable macOS installer. Simply use the Terminal command by copying and pasting the command line for the version of macOS from the list below. You will need an 8GB or larger USB flash drive that has been partitioned and formatted for use with OS X as well as an installer for the desired macOS version that you have previously downloaded from the App Store.

Drive Partition and Format

1. Open Disk Utility in the Utilities' folder.
2. After Disk Utility loads select the drive (out-dented entry with the mfg.'s ID and size) from the side list.
3. Click on the Erase tab in the Disk Utility toolbar. Name the drive, "MyVolume". <---- IMPORTANT!
4. In the drop down panel set the partition scheme to GUID. Set the Format type to Mac OS Extended (Journaled.)
5. Click on the Apply button and wait for the Done button to activate. When it does click on it.
6. Quit Disk Utility.

Create Installer

Open the Terminal in the Utilities' folder. Choose the appropriate command line (in red) depending upon what OS X installer you want. Paste that entire command line from below at the Terminal's prompt:

*Command for macOS Mojave:

sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

*Command for macOS High Sierra:

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

Command for macOS Sierra:

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ Sierra.app

Command for El Capitan:

sudo /Applications/Install\ OS\ X\ El\ Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ El\ Capitan.app

Command for Yosemite:

sudo /Applications/Install\ OS\ X\ Yosemite.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ Yosemite.app

Command for Mavericks:

sudo /Applications/Install\ OS\ X\ Mavericks.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ Mavericks.app

Press RETURN. You will be asked for your admin password. It will not echo to the Terminal window. Then press RETURN again. Wait for the return of the Terminal prompt signifying the process has completed. It takes quite some time to finish. Be patient.

* If your Mac is using macOS Sierra or earlier, include the --applicationpath argument. The Sierra and El Capitan commands show the proper format of this argument.

The bootable installer can be used to install the selected version of macOS. Shut the computer down. Insert your flash drive into a USB port. Start the computer like so:

Boot Using OPTION key

1. Restart the computer.
2. Immediately after the chime press and hold down the "OPTION" key.
3. Release the key when the Boot Manager screen appears.
4. Select the disk icon for the USB flash drive.
5. Click on the arrow button under the disk icon.

Read here how to make a bootable installer with DiskmakerX:

http://osxdaily.com/2018/09/26/make-macos-mojave-boot-usb-installer/

Here you can download the full Mojave installer (6.1GB):

macOS Mojave

It is mentioned that you need a 16GB stick, but I used a 8GB stick and that was enough.

Have fun.

I haven't tried the above tips but...

Macrumours has a discussion on this. It seems that Mojave only supports streaming updates. At no stage during the installation process did I find a large installation file that I could copy to another drive, as with previous OSX/macOS.

It is not difficult:

first you have to download the FULL Mojave installer, about 6GB !

You can do that as explained here:

http://osxdaily.com/2018/09/29/download-full-macos-mojave-installer/

The rest is standard: either with Terminal or with DiskmakerX. You need minimum 8GB stick.

Lex

Wrong address: NEVER download apps from a aggregate site: often the installers are manipulated with adware and/ore malware. Download from the developers site.

You can test downloads with Virustotal:

https://www.virustotal.com

You have to do it while having a full installer file in the Applications folder, and better use DiskmakerX latest version. I did it from High Sierra.

DiskMaker X 8.0.3 free download for Mac | MacUpdate