Pixel Dungeon

For mage... you can go battlemage and put the scrolls of upgrade into the staff... easier, since I do not have to hoard my scrolls until the end of the game.

This is not unique to Battlemage. Not sure what gave you that impression. You should put your first few scrolls into the staff even if you plan to be a Warlock. Hell, I usually put my first 7 scrolls into the mage's staff to make it have 10 zaps (staff of magic missile has 3 zaps at +0 instead of the usual 2, so at +7 it has 10 zaps).

You can apply the warrior dump-all-scrolls-on-scale-armor on every single run, with every single character, and then the game becomes just easy. Except on Faith Is My Armor, you can't there.

The distinct advantage huntress has is the bow, which let's you whittle down the hp of enemies before you go into hand to hand combat. It is also important to note that your bow can be enchanted, which it is a good idea to do as soon as you find a stone of enchantment, since you use the bow the entire run.

If an enemy is right next to you, and you step away from them into tall grass, and then you step away from them again, your next melee attack will be a surprise attack and won't miss. This is because—for a split second—they couldn't see you while there was tall grass in between you. This is because you move first, then they move. It happens very fast, but for a time, the tall grass was between you.

In addition, if you don't attack them, and instead step away from them into another patch of tall grass, they will get confused (and show a "?" above their head) and now they have given up on chasing you and will move in a random direction.

Only the Huntress can do this because every other class will trample the grass.

Grass breaks line of sight. (Not when you stand in it, but when it's between you and an enemy)
A single tuft of grass allows you to infinitely surprise attack an enemy if you just run in a ◇ around it, attacking every other turn. (Same a single stone pillar) Fishing with the huntress is trivial which saves you an invisibility potion and gives you the fishes' meat for food.

I personally don't like the sniper much, but love the warden. The skill that gives you barksin when trampling grass boosts your armor a lot.
The skill that regrows grass every x turns makes the barksin almost always up, not to menton the extra dew and seeds.

I think especially with the huntress, kiting and positioning is important.
You can break away from an enemy as long as you have a single square of grass or stone. Like with the surprise attacks by going around it in a ◇ pattern.. just move twice without attacking them and then away.
Helpful against skeletons, not so much against crabs.

You can cook spent darts in the alchemy pot with seeds to recreate whatever effect, not that I use darts much.

Using a (+) rune on the bow is nice because the bow's upgrades can't delete those.

If you find a ring of sharpshooting I'd pump some scrolls into that instead of into the weapon. Makes the bow OP. Projection enchantment is also great to snipe enemies through walls.