in the daytime i use the karve to look for a crypt close to the shore
make a quick landfall, kill everything before they kill you -draugre are slow and fire arrows work well. poison resistance is vital , smash all leaches , put down a workbench , jump into crypt - get 10 iron and build a longboat - all swamp landings can be done this way and get much easier with a longboat , scout the shore from a safe distance , if you see mobs or blueish looking things find another spot , sometimes black ofrrest rocks stick out from the swamp you can land there too - same process - kill everything and drop a workbench - 10 wood
some say dont land in the swap but i always do with the above method- the workbench helps keep the boat repaired as you truck iron out to it - bonemass swamp i drop a portal in a raised shack usually or if its a swamp with lots of crypts ....bloodbags can be portaled - i love me some bloodbags
eliminating spawn pools in the stone circles can calm a swamp down in a hurry , it could even become peaceful
you only need 10 iron to start really , with a longboat you can start travelling the world
swamp abominations are just trees , chop them down , burn them a bit first if you must - they run away , dont follow, its a ploy to engage more enemies, if you eliminated the spawn pools you can follow them , otherwise they are just looking for friends to join the fight
use the longboat to get serpents and use their scales to make the shield- its a good shield until later when you get black metal
abominations let you make the root armour
my last seed had an awesome bonemass swamp on an island with a swamp river separating it from another swamp , no way to get there from another biome , you had to land there