If there's a particular menu option you use all the time that doesn't have a shortcut, you can create it yourself.
Go to System Preferences > Keyboard > Application Shortcuts. Click the + button to add a new shortcut. You can choose which app you want to apply it to from the drop-down list, but you must know the exact name of the menu command to type into the next box, including the correct case and any special characters such as ellipses. Lastly, choose a unique key combination to invoke the command, then click Add.