Remember, on most maps you won't find a site with everything you want. Heck, finding flux and a magma pipe (a reasonable amount) is somewhat rare. Then trying to find Magma, Flux, Elevation, trees, an above/underground river, a chasm/bottomless pit, sand (which IMO, is necessary), unhaunted, no damn unicorns, a side covered by the ocean, easily covered areas, etc is close to impossible.
I usually go for a nonevil place that will have animals, sand, a good amount of trees, flux, and a river, though I guess a brook would do fine I prefer a good Ol' river for defense. If I can find it, I like to also have a magma pipe which then I can have a few less trees, an underground river instead of a river/brook which then I can do with even LESS trees, and if I am completely, insanely lucky, a chasm or bottomless pit!!
Now if I'm messing around, the best place I found was the one freezing Haunted/serene (or some other evil/good status) tundra, completely half and half. So I had skeletal dudes raging the unicorns and crazy death followed. Good times, good times.
Now what you could do is mess with your INI so it shows on the map the magma and underground stuff (like our good captain duck) and then keep making maps till you find what you like. But again, some animals, flux, sand, a river, and some trees will do you fine. I'm still annoyed that my perfectly good biome has NO wild animals.