Ok this is going to be a base for a character called Eurynome, from helldorado miniature game. The idea is he’ll be standing on rocks coming out of water, and there’ll be corpses in the water. Should be suitably gruesome.

Fist cut out centre of the plastic base so you end up with a ring. I’m using a large war machine base here, official helldorado bases are much harder to cut, the plastic is thicker and possibly harder.
Put the ring on a piece of cardboard, and with a sharp pencil circle inside edge of the ring.
Cut out the disk with scissors. It should fit inside the ring without leaving gaps.
To make the submerged corpses, make some milliput moulds from any undead miniatures. Make small milliput discs about 5 mm thick. Rub the top with Vaseline before pressing miniatures into it, so milliput doesn’t sticks to the miniature.



Put the plastic ring over the cardboard disc. Stick some milliput casts to the disc with superglue. Arrange them in an interesting way, but leave some space for the rocks.
Fill the space under the ring with milliput. You might want to use a couple of drops of superglue here and there to make sure milliput sticks to both the ring and the disc. This should create a basin for the water effects.
Take to peaces of milliput stick them to the base with a drop of superglue. And shape them to roughly resemble you rocks. You don’t need to be detailed at this point, but areas where miniature will connect have to be defined.



When milliput hardens, but still soft enough to be cut. Carve you rocks to make the shapes more interesting.
When completely hardened, add more details to the rocks with milliput. And fill the gaps between the milliput casts. If you want you can also stick some gravel, sand or green sawdust in places with PVA glue.



Paint the base.



Water effects shrink when dry so several layers have to be applied. Bottom lair have to be completely dry before new one is applied. I applied 6 layers of Vallejo water effects here.