What is the safest way to kill blazes?

What is the best way to kill blazemen without losing any health? If I just shoot them at a distance they can easily take 6-8 hearts off me by setting me on fire with their fireballs. Fire resistance potions aren't good enough because I still take damage (1 full heart) when they touch me.

Use lots of snowballs. They do 1½ hearts of damage each to Blazes. If you can't make potions, diamond armor definitely helps with fire damage; iron does not work so well. Potions of fire resistance are a good idea though. If you can in the Nether, build some snow golems, though they wil probably get destroyed quickly.

Use Fire Resistance potions.

If you don't have access to them yet, make sure to stay at a long distance from Blazes and just shoot them with a bow.