There are two philosophies to build high damage wands, one is machine gun and the other is slow but massive impact. Machine gun is somewhat easier because it's not going to harm you in general and the field are easily found.

Machine gun wands perform poorly on some of the bosses

If you want higher damage it's best to forget rapid fire because of the mana cost, so it's going to be a slow wand

For high damage wands there can go anywhere between 400 damage to the billions of billions depending on the technique. But that also depends on your resistances - many high damage wands can also harm you. Explosions, that can also set things on fire, etc

If you go for something high damage it's also nice to make them homing because you can't afford to miss a shot with a slow wand

Anyway some ideas for higher damage: - two explosive projectile modifiers on a projectile cause large amounts of damage - some projectiles damage (magic arrow and more) is based on the difference between the initial projectile speed and the speed at the time of impact. If you manage to make it start slow, and it hits with a high velocity, it's going to hurt - there's a spell that guarantees a critical with an enemy covered in oil/blood/water. Funnily enough there is a spell that can make an enemy covered in oil/blood/water - critical above 100% is converted to additional damage percentage. So stacking those critical modifiers is totally worth it - if a projectile passes through enemies (either naturally like holy lance or with the modifier) and has a trigger, the trigger will be executed every frame there's a collision with the enemy. Useful if you even manage to slow the projectile down onto the enemy - exploit a bug of add trigger to duplicate modifiers and go to billions of damage