Just got mine yesterday, and few sample burns went well. Was just curious if you guys had ideal power/speed settings for various types of material? I’ve seen a few settings for the Neje app, but they are seem to be quite different.
Hi, different materials need different settings, some people like a dark burn some a lighter burn, so there’s not really an answer for that.
It’s all trial and error, use waste material until you get the settings for the project correct.
once you get the settings correct, use small adjustments to speed and power and try to do them in less time… 
30w module.
3mm birch plywood to cut perfectly, 220mm speed 100%power 3pass.
Focusing:
For cutting stuff effectively, is important to focus under the surface, so the focal point needs to be around half in the material, in this case, 1.5mm below the surface.
For engraving.
if you put a black paper on the surface, when fire the laser (for me 0.01%) to be strong enough to see and focus, there is a “buzzing” sound appear when the focus on the surface perfect , and when you move the test paper the laser leave a thin line and smoke.
And then you need to push a focal point into the material…
it is need a few test engrave and cut session…
Been trying to perfect engraving tiles, so far 2 weeks in 
Different paint burns differently, different colours burn differently, different pictures need different settings etc, etc but enjoy the learning…
Well I been experimenting with fired ceramics. Also to make note here I have the 40 watt module. I have engraved LoFire ceramics at 50% 150 mm/min. This is unglazed material. I noticed a color difference in the engraved parts when I compare the results to the one I get with my K40 CO2 laser.