I thought I would share my strategy since it has worked so well for me.
First - Less is More! I generally only take what i NEED to kill the boss and its minion/s plus one extra attack... thats it. but i DO keep at all times a reshuffle in my deck in case something goes wrong.
Second - Keep it simple! When i set out to kill a mob, i set up so that i can one hit kill each mob including the boss. Some times this gets a little crazy like when you are fighting four mobs at one time, but most of the time it is pretty straight forward and easy to pull off.
Third - Know your damage. know when it is ok to attack, and try not to over buff the mob. if a mob only has 1120 health there is no need to be doing 3800 damage just to kill it unless you really need the health. this means experimentation: test different combinations of traps and blades to find out just exactly what kind of damage you will get from different combinations.
Last - Know how to maximize damage. This is mainly for bosses with high health only, you wont need to use this for minion mobs or run of the mill encounters. below i have listed (as far as i know) the highest possible damage combination you can do as a death wizard, PLEASE experiment and pick stuff you like and toss stuff you dont need, this combination is litterally double the damage you will need to one shot kill any mob in the game.
(rules: life trap goes before prism, and death traps go after prism)
Life Trap - You can actually train this spell in wizard city at one of the hidden trainers
Life Trap - Treasure Card
Death Trap - Bastilla's Deadly Choker (bought from Marleybone for $1020)
Spirit Trap - Treasure Card
Spirit Blade - Treasure Card
Balance Blade - Royal Tunic of Balance (Prospector Zeke or wizard city robe shop)
Wraith - Royal Boots of the Wraith (Prospector Zeke or wizard city boot shop)
Hope this helps,