This is an AD Cassiopeia guide i made by myself. I was testing it, and it dealt awesome autoattack dmg, well her spells dmg a little lower with the AD, but her auto-attack hurts alot. It is also easier to last-hit the minions because u dmg more to them with the AD. Try it out! :)

Why i chose that kind of seals is because AD Cassiopeia goes very fast out of mana. I take the mana regen and some mana potions in the start for keeping my mana up.

In my Utility i also take the Expanded mind and the mediation. As i said. The mana of an AD Cassio is gone earlier than when shes AP. The Trinity Force will help your mana problems alot. You can also chose to take the Trinity Force before the Black cleaver. But why i choose the Black cleaver for first is that lovely armor reduction to your target.

I chosed to take the Phantom Dancer because i like the movement haste and the crit.

Ignite: I didnt took the ignite to finish them off. I take it because of my Summoners Wrath to reduce down their armor. So try to put on the ignite and burst for a damage output.

Flash: I took flash because i play mid with this AD. When Cassio is AD i think she would be able to carry with a support down the bot-lane. So she could also take the Exhaust instead of flash when you are carry

You need a blue buff, if you may farm it of your jungler, it is so great. Then the AD Cassio is not running low in her mana.