Actually, Killing with vlad takes a bit of practice. He isn't really a burst mage, so it really makes it hard to judge when you can kill with vlad. I don't like Taking Flash, simply because all your damage isn't in one burst. It's often chunking away someone's health, over a few seconds. Ghost allows him to stay within reach of his enemies, and retreat with relative ease.
Harass with Q, as often as you can. Don't worry about Tides until Team fights start, or you are going for a kill. If you can get it off, great, if not, it's not really a huge amount of damage unless you are stacking it, Which isn't advised until you can do quite well with Vlad. I might suggest Rylais as your first major item, as it provides a slow with your Transfusion (Trns) which will make those kills a lot easier.
The last thing I'll say about Vlad is he is a mage TANK. Take advantage of that. Build Zhonya's, Abyssal, Rylais, and abuse his more tanky side. Those three items, plus WotA will make you harder to kill, hard to run from, hard to chase, while still giving you decent damage and killing power. Throw in Visage for the CDR and Sorc shoes for the Penetration. If you are still having issues killing, replace visage with Guise for an additional 20 MPen. Your Cooldowns suffer, but your damage becomes greater.