/menu create [menu name] [rows] [title]

[menu name] name of menu, all 1 word. Players will not see this.
[rows] how big the menu should be. Can be between 1 and 15, though any more than 6 will cause visual glitches.
[title] the title of the menu. As many words as you want, you can use colour codes. Players will see this if you give them access to the menu.

Hold the item you want to add commands to and type
/menu script append [command]
[command] command you want to add to the item. Make sure to include the /.

Don't use curly braces (These: '{' '}')
@p is replace by the players name. If you want to use it as an selector run '/execute @p ~ ~ ~ ' in front of your command, and replace @p with @s
By default the console executes the command. If you want the player to, run '/execute @p ~ ~ ~ ' in front of your command

Once you have added the commands you want to add to an item, hide them with
/menu script hide
If you want to show them again use
/menu script show

Once commands are hidden, you can use
/menu script append [lore]
[lore] one line of lore you want to add to the item. You can use colour codes.

You can rename an item by holding it and typing
/menu script title [name]
[name] new name of item. You can use colour codes.

You can add an item to an menu by typing
/menu edit [name]
[name] name of menu.

Place the item wherever you like and close the menu.

You can run
/menu open [player] [name]
[player] player you want to open the menu to. This is optional.
[name] the menus name.
to open a menu.

You can add
/menu open @p [name]
[name] the menus name.
to the commands of an item to make a menu open when they are right clicked.

YAY I HAVE 50 POSTS!!!
That is 1/5.14 of partydragen's posts
That is 1.13636364 times more posts than Frozytime
That is 1.72413793 times more posts than Ninjune1

I think I have the highest post count of any member.