Seei have been playing her a bit different.
1. always get boots + 3 pots to start.
2. Boots--->berserkers
3. phage
4 Zeal
5. Phage & Zeal ----->Trinity Force for the amazing stats that pretty much benefit her more than any other champion besides maybe wukong.
6. Sunfire cape because i max out my Burnout asap. I love the extra AOE dmg
7. Raguso rage blade
At this point in most cases the other team has lost. the last few times i have played this style i single laned and went between 10 and 14 kills with around 3 to 5 deaths and 4 assists.
I rock armor penetratio marks, Flat AR seals, Flat MR Glyphs, and i rock Attack speed or Critical strike quints. My masteries i rocked the standard 24/6/0. The reason why i don't get the utilites is cause i play aggresive and i don't really need them. I prefer the hard hitting/ Tanky shyvana.
If the game continues on past me aquiring Raguso, i usually pick up a Nashors Tooth, or Black cleaver depending on what the team is like.
Try this out. Whatever you do max burnout as quickly as possible. Most champions won't commit to you because your burnout is active. If they are stupid enough to ditch the sunfire cape and pick up thornmail. It will really make them think twice once you drop there armor and than start poiunding them from burnout thornmail and Dragon strike.