Combo Fields and you.

found a list of what combo fields give which combo today, the external links for what each combo doesnt didnt transfer over it seems.
if anyone wants to know what something is, please ask.



Dark:
Blast. Area Blindness
Leap, Blindness
Projectile, Lifesteal
Whirl, Leeching Bolts

Ethereal:
Blast, Area Chaos Armor
Leap, Chaos Armor
Projectile, Confusion
Whirl, Confusing Bolts

Fire:
Blast, Area Might (3 stacks)
Leap, Fire Armor
Projectile, Burning
Whirl, Burning Bolts

Ice:
Blast, Area Frost Armor
Leap, Frost Armor
Projectile, Chill
Whirl, Chilling Bolts

Light:
Blast, Area Retaliation
Leap, Retaliation
Projectile, Remove Condition
Whirl, Cleansing Bolts

Lightning:
Blast, Area Swiftness
Leap, Daze
Projectile, Vulnerability
Whirl, Vulnerability Bolts

Poison:
Blast, Area Weakness
Leap, Weakness
Projectile, Poison
Whirl, Poison Bolts

Smoke:
Blast, Area Stealth
Leap, Stealth
Projectile, Blindness
Whirl, Blinding Bolts

Water:
Blast, Area Healing
Leap, Healing
Projectile, Regeneration
Whirl, Healing Bolts

Here's an excellent diagram showing which professions can make which fields - it also shows the effects of all possible combos.

It's a little bit inaccurate/out of date because it doesn't list all the effects so just ignore where it says nothing or unknown.

most of the different types of field+finishers follow a pattern:

projectile - will cause a "related" condition (e.g. fire field + projectile = burning)
whirl - is like an aoe version of the projectile finish (e.g. fire field + whirl = burning bolts in all directions)

leap - will cause an aura or some other positive benefit that is related to the field, but stronger than a simple condition (e.g. light field + leap = retaliation)
blast - is like an aoe version of leap, usually gaining a similar benefit as the leap but AoE to all party members or enemies (e.g. light field + blast = aoe retaliation)

ofc there are exceptions, but in general whirl finish is like aoe projectile finish, and blast finish is like aoe leap finish... knowing this we must prioritize our whirls and blasts to make sure we are using them to their full potential.

one other thing to note: the effect of a finish will depend on the field that was laid first. e.g. if you lay a long-lasting field down like say healing spring (water field), then a few seconds later you put another field on top of it (e.g. ring of warding's light field), then a blast finisher will trigger AoE heal and not AoE retaliation.