This is every item I buy in the order that I buy them. The Vampiric Scepter can always be bought earlier, but I never find it necessary to buy earlier as Tryndamere can heal for so much. If the enemy is stacking up on armor, grab Last Whisper before The Bloodthirster. If you're against a Dr. Mundo, grab a Madred's Bloodrazor instead of the Frozen Mallet. There's always situational items, so be sure to adjust to your team's needs and to the enemy team's composition. If you completely finish the build, swap out Berserker's Greaves for an additional Phantom Dancer.

This is my full setup for how I build Tryndamere in 3v3, I've found it incredibly effective. The masteries that I use are for a Tryndamere that will be going into the jungle to grab buffs whenever possible after level 6. I always go top, unless there's a really good harasser, and in that case I play as defensively as possible until level 5, then I start jungling. Mid to late game nobody stands a chance. Not to brag, but while using this build, I've never lost to another Tryndamere in game. Ever.