I like to look at the picture area of this forum to get ideas. But I'll babble out some of mine cause I like to.
I'm assuming this is a standard shape 38g which is probably 36 inches long....
I would do one of these two things:
Sand bottom 1/2 - 3/4 inch (around 8 -10 lbs)
flat, rounded rock piled up long ways (not touching the sides) silicone together (i'd think it would end up coming 3 inches from any side and being about 8 inches high.
or:
a shell dweller tank with the same sand and all kinds of shells in the bottom. then a couple large rocks (rounded but more spherical) scattered around (probably only 3 of them).
I'm assuming this is a standard shape 38g which is probably 36 inches long....
I would do one of these two things:
Sand bottom 1/2 - 3/4 inch (around 8 -10 lbs)
flat, rounded rock piled up long ways (not touching the sides) silicone together (i'd think it would end up coming 3 inches from any side and being about 8 inches high.
or:
a shell dweller tank with the same sand and all kinds of shells in the bottom. then a couple large rocks (rounded but more spherical) scattered around (probably only 3 of them).