Full stop

One way would be to automate the activation of the mute buttons at that point.
 
Another would be to render all your Midi instruments to Audio (Bounce to tracks or freeze) and then you can slip edit the wav files right in the track view.
 
Let us know what approach you take and have fun being creative :-)

ha100
Hello,
I've been trying to figure this out for months. I can't seem to figure it out. I just want to create a full stop in my project. A sudden total stop of sounds. No echo's of instruments or whatever. I think this is what is called the drop in modern music.
Can someone tell me how to achieve this?

You can automate mutes or the master fader as mentioned above. You'll probably find you don't need to mute everything to make the effect. I usually create a sub named Fader that gets automated when I need to do something like that, that way I don't have to touch the master. Same difference though.
A bit of terminology, normally a drop refers to the loudest most energetic part in modern music as in when the bass drops. A quiet part is usually referred to as a breakdown.
 

I agree with automating volume envelope(s).
 
You will probably find that automating mutes are way too abrupt and could result in nasty clicks if it doesn't occur at a zero crossing.
 
Depending on your buss structure, I'd be inclined to put volume envelopes on your individual busses, this is more precise than automating the master buss and less of a chore than automating all of your tracks.