I use braid line was curious what lb test you guys usually use for lmb fishing or if there are factors it depends on? do you usually use a leader as well?

I use 50lb, 65lb, and 80lb braid.

50lb braid I typically use a 10-15lb leader if needed, and 65lb I usually use a 20 or 25lb leader if needed. I never use a leader with my 80lb braid.

Different techniques call for different line types and size.

I don't flip or pitch much, but I use a baitcasting rig regularly. Mine if filled with 30# test PP and a 17# test fluorocarbon leader of about 3'. Has worked well for me for years now.

You could probably pull over a tree with 30# braid. Not really convinced heavier line is a true necessity....but I could be wrong. To each his/her own. 

55# samuri braid..I use a 10 or 12 lb leader..mostly 12, even though the dia. of 12 is slightly larger, where the 10 is the same dia. as the braid.

Leader vs no leader depends on water clarity and structure thickness. I typically use 40 and 50 lb braid. I do not use a leader if I am using it for topwaters. If I am flippin/CR/etc in clear water I usually use a 2-3 foot fluoro leader (17/20 lb). I cannot tell you that the visibility makes that much of a difference, but it gives me more confidence so I am not second guessing myself all day.