A delay can be achieved by pasting the same channel data into another channel but with a slight... delay. This is easiest in IT format where you can set the channel volume for this echo channel to e.g. 30% and hence do not have to adjust all volume commands manually.
Old topic I know. I just wanted to add my two cents:
I'm very familiar with the "ping-pong" technique by copy/pasting channels for delay. I've done it in the past using as many as four channels. while it does have limitations, it does work well. Believe it or not, the Carpenters invented this trick using vocals to create depth and harmony and called it Ping-ponging (which is why I use that term).
The most important trick however has to do with actual sample creation. Prior to plugins, you applied effects to your samples prior to importing them into a project. In many cases, they couldn't be looped, so you would opt to record a long sample, as long or short as the instrument would need to be sustained in a given song or track.
While the audio editing software back in the day was quite limited, even in the days where .VOC files dominated the .WAV format, many audio editors allowed you to apply effects to samples. When I didn't have that option for a particular effect, there was another option... My brother is a guitarist, and he has (and had in the past) a LOT of effect pedals. I would sometimes borrow them to chain for effects when recording a sample off a line source or a microphone. Delay, reverbs, distortion, echo, wah wah, flangers, ring mods, you name it.
Nowadays, a lot of audio editors and DAW's support VST or MAX plugins so it's becoming a lost art, but pedals are always an option, still to this day!
I think I actually used a desk fan in front of a microphone a couple of times when making samples. Nothing is off limits when actually making the samples you use in a project and it helps a lot when using old school trackers that don't support pliugins.