Garry's Mod Workshop Utility (Easy create, upload.etc).LuaWorkshopper - Quick tool for Addon making and publishing.Garry's Mod Easy Addon Uploader (for Windows only).

Garry's Mod Publishing Utility - Java based GUI wrapper.gmpublisher (GUI for Windows, macOS and Linux).Links to such known tools: (feel free to expand) You can use alternative tools such as GUIs (graphical user interfaces) made by community members to create, extract and upload addons to Steam Workshop. Please see this page for complete set of rules:

There are a few rules before you start uploading addons.

To download an addon, just click on the addon you want from the list.and then click the download box.This article will teach you how to prepare and upload an addon to the Steam Workshop. These show the latest addons people have added to and the most popular (most downloaded) addons.these are helpful because you instantly know what new addons have been added to the site. Just below the tag box, there are two columns, one labeled latest.and one labeled popular When you first go onto you will notice a big square filled with lots of different words, these are tags and you can just click on one and it will take you to all the files associated with that word.this saves time typing :) there is also a search box where you can search for addons. Now for the addons you can get the addons from they are all free and you dont need to buy them.i wont go into too much detail about how to install complicated files.but i will show how to install the basic but most needed ones, the most needed ones in my opinion are the pheonix storms premium models pack.as they open up loads more materials to create things with.

Gmod file addon