Maybe add a camp netting over the top, or add a table with some maps on it+radio.
everybody does that stupid stacked cylinders with a 1 brick offset every other layer thingi suggest trying to set yourself apart from the norm, and do something that isn't that.
How else can I do sandbags?
Use things such as ammunition boxes and more barrels as a part of the barricade itself, not sitting against the barricade.
Because using explosive shells as barrivade is totally fine