This is my basic build for Tryndamere. Its nothing special just what i tend to use to rapeinate the other team.

I choose a pretty standard 21/9/0 build. Many people like to go off in utility for the other 9 points but theres nothing in utility particularly useful and since I like dodge seals I love the speed boost in the defensive tree.

Armor pen quints are delicious. They help your damage against everyone people seem to forget that :P I used to want all crit chance marks but now im leaning more towards crit dmg marks because with the items you get in this build your crit chance will be above 80%. I didnt see anything in particular i wanted for glyphs so i went ap per level for the bonus it adds to bloodlust heal and spinning slash.

I get crit immediately to help boos my Bloodlust stacks early on since i got crit dmg instead of crit chance. The heal from 8 stacks of Bloodlust can easily keep you in the lane in early levels before you get life stealing but i go ahead and get 2 healths pots as well. As soon as i get Avarice blade i grab my boots then rush Phantom Dancer one of the key items in this build. By the time you get Infinity Edge you will be auto attack critting for 1100+ easily and thats not even counting your other Bloodthirster. Another option instead of your second Bloodthirster is some armor pen if you are fighting tanks stacking armor. I prefer black cleaver for the massive amount of dmg on it.

Summoner spells are really take your pick. If im with people i know i go Flash/Ghost so i can chase people down and slow them. Ignite is fine as well but i wouldnt use exhaust since you already have a slow. Cleanse is also a standard for me its lovely when people think they got enough dots on you to kill you after you spin away cleanse and heal to half health :D.