To be the ultimate Bosmer Marksmen read this guide.
You get a +10 to your Marksmen skill so it's advised to be one and pick or make a class
that has marksmen. as for birth sign "The Shadow" works quite well for when you want to be
unseen.
As a Marksmen you can climb up on high things so your enemy can not reach you. i find it
nice to climb on top of a roof then start a guiard and citezen killing rampage!
If there is an enemy Marksmen nearby do NOT stand still sidestep to avoid being a
pincussion. also close doors to get free arrows. guards tend to have better bows than you
when you are at a low level so set the difficulty to veeeeery easy kill the guard and take
your awesome bow.
If you sneak around hide in a shadowy spot then shoot the unsuspecting foe for a sneak
bonus or 1 hit kill.
This here is random but if you dpo the DarkBrotherhood quest where you are to kill Adumus
Phillida with the 1 hit kill arrow "Rose of Sithis" you could easily climb on a nearby
roof sneak and TWAAAAANG he is dead.
I hope my walkthrough was useful. Happy shooting Bosmers!!!