I prefer to add a laser to my silk+crystal ball spell, since unlike regular weapons which just create a silk projectile in the space they just passed through, lasers seem to create a projectile at nearly every single point in their trajectory at once (and many many times each spellcast), the results are: A) Even greater damage, B) spawns many more projectiles, C) instant travel time of the initial beam (which makes things die faster as the targets spawn close to them near instantly), D) The fact that many of the projectiles spawn far away doesn't really matter, since enough spawn closely enough to kill even a boss in a single hit.
Now, it does have two problems, A) The homing on them lasers is better then regular attacks, which means they are more likely to hit the target (and not miss, which causes even more obscene damage, not really the biggest problem, since even a direct hit will kill pretty much anything instantly), B) using a laser takes up a spell effect spot.
I would *really* like to see some of the combinations that would be possible with 5+ spell slots though, (EG. laser+homing+silk+split shot+other split shot+travel through walls+travel through enemies+chaos).
Honestly, silk+crystal ball is the best spell by such a wide margin it breaks the game and takes away the whole "explore different spells" concept, since there literally isn't any possible spell combination that is anywhere near as good.