Numbers added in quote below, for reference...
1. Remembering on my end to add +X to attack and damage while keeping it mysterious from the player
2.Keeping track of unknown magic items and telling players to refer to them as "Magic Sword you found in Room 17 of The Cupcake and Pastry Dungeon"
3.Spending half an hour in a game of 20 questions every time the party finds a magic doodad
4.Spells requiring 100 gp pearls and/or a wizard in order to be able to tell basic information I'd rather not keep track of.
For 1 and 2 above, item numbers are your friend.
Party finds a magic ring of unknown purpose. You note it as item #87 on your DM's treasury list, along with what it does; whichever of the players is keeping treasury notes it on her list as #87 - Ring. Then when a player reminds you "Hey, I'm wearing ring 87" you can quickly look it up and remind yourself what it does, if you've forgotten. The players can also put on their list any field-testing results they get e.g. "not flight or speed, not water-walk, might be water-breathe but nobody really wants to test".
For 3, above, most parties eventually develop a testing procedure once they've encountered various things items can do; this to me is no problem.
4 is used back in town when 1-3 fail.
slobo777 said:
Now a character forgetting he was wearing the unidentified ring, and wishing out loud for a cup of hot chocolate (and then getting it) was a thing of epic-always-to-be-remembered fun of course . . .
In my game it was a feather bed, deep in a dungeon, that would not fit out the door of the room it appeared in.
That was 15 years ago, and the player still hasn't lived it down.
Trial-and-error field testing for the win!
Lan-"years ago I, in character as a so-called dumb Fighter, wrote our group's field-testing guide"-efan