When your stream of objects in a glue or tar gel base is dry, remove it from the form and check how it drapes. You don't want one part to droop below the base, due to the heaviness or concentration of many objects in a single part of the stream. The stream should drape naturally when you hold it, and the objects should be at varied angles as they would if being poured from a bucket or box, whatever you are trying to immitate. If you have large open areas in your stream, fix a few more objects into place to fill up the line.
Check that the length of your frozen moment pour is going to reach from just inside one container, to the fluid level of the receiving container. If not, add more objects to the upper end of the pour to lengthen it.