Not Updated For Current Season
If you've been reading around Tryndamere is a pain at low lvls.. So your basically going to either have an awesome partner to kind of carry your lane or you can just tower hug and until your lv 6 or so.
First things first..
I always get Cleanse and Flash for my abilities.. Cleanse because getting stunned sucks and not being able to Ultimate yourself from death is no good.. cleanse is also nice at low lvl's when your getting ganked.. it has a fairly short cool down of 120seconds.
Flash - I use flash because its almost needed with Tryn often enough I'm the first person to run into a team battle. And it mostly will last no longer then 10 seconds atleast for me.. I take as much dmg as I can then Ult.. and 5 seconds later I spin out of the fight, flash and hit my bloodlust to heal up( Cleanse if DoTs or something are on you)..
Starting out --
Starting items I usually will go with boots and 3 health pots.. Trust me your going to need those health pots..
For my first ability I always pick up mocking shout.. I'm sure many people would be like what for? Well its awesome because it reduces your enemies dmg by 20 and its a snare as well. Not to mention if you have Pesky Invisible Enemies you can Mocking shout them when they are near.. Which tells you they are near and you can either get the hell out or prepare for a battle!..
If your lucky and your lane partner is holding your weight well enough that you got some decent gold.. I would recommend picking up Executioner's it gives you 18% Lifeleech and 15% critical strike.. Which is needed!
You should be about lv 6 by now so Jungle it up! Really the only way Tryn can make money. And you should be able to kill just about everything with the Executioner's
After making some more money pick up a zeal.. which is more crit and attack speed.
Then pick up 18pct crit cape.. You should have around or more then 50pct crit. Now you can start picking up some damage. Start building the Infinity.
Your crits will be hitting for 600 dmg or so now and you should be criting alot..
After You get infinity's edge I would recommend making a Phantom Dancer.. this will put you up near 70pct critical and it gives you the attack speed..
By this time it should be fairly late game and you should be a beast.. hitting for 600-700 dmg always ever hit.. So what you should be getting is Attack speed. So you can just output even more dmg.. Unless you are really having problems staying alive.