I may be a noob, or maybe just unlucky. I have been housed on 2 worlds (Furthor and Yugen) for about 1 month now and have never ever found gleam. Here are my questions.
Any coaching would be appreciated!
There are worlds where you might find some on the surface, but generally it’s in caves.
I have been in some awesome cave systems. Still no gleam, above or below water. Dang it!
Cahnged the topic from guides as that category is for guides and not asking for help with a problem 
one name: storial ^^
just look for some floating isalnds and boom you’ll be drowning in gleam
Sorry about that and thanks!
The worlds are online for quite a while now and world-regeneration isn´t implemented yet, so only the best hidden gleam-depots are still present.
If you want to tell me were you live I´d gladly place gleam of every colour there (you can then dublicate the blocks using infinite mode (by pressing “,”))
Thanks @Vastar. I’ve gone and done that myself. I was just hoping to find it on my own. There’s an excitement factor to it for me, kind of like finding Diamond in minecraft. I appreciate the offer though!
Well good look with your hunt then (Going to be quite a challenge to find all 14 colour variations )
I’ve got a line on a pretty abundant source of red, if you have need.
Actually someone made a list of worlds at some point right?
@ThavenMooncrow Most of the gleam world locations should be here. I can’t remember if we made a collected list though.
Honestly, I’d just like to find it naturally in the world Haha. I’ve tried every suggestion and still not seen it in its natural setting.
Gleam is somewhat particular to some biomes. If you find a cave that has no gleam in it, try finding a totally different biome and look for a cave there.
Thanks, I’ll try that!
There is a list here, click on the world to see it’s gleam. 
hope it helps!