Oh, okie Starting with the walls. I donno, pick something bright to match the snow. Whatever here, flip a coin. Heads is abandoned mine, tails is crypt. Cuz it hit the table.
Crypts are straight lines.
Make it a crypt. Now lets add some life. Argh just take several monster parts, mix and match them with no concern for dungeon context, physics or fundamental aesthetics. But make it undead, cuz it's a crypt and all. That's why we got gravity.