I can Tell you my setup for Hotbar on PS4. Its in no way perfect, but I find it very effective. First, I put all the abilities that I use most often on my main Hotbar, and the spells I use slightly less often are on the R2+L2 expanded hotbar. I have very little use for the second hot bar, but use it rarely. This is just my opinion of course, but this is what I would suggest to new BLMs trying to find an ideal setup.
Main Hotbar (R2 is my primary attack trigger, but I've noticed a lot use L2 so whatever suits your fancy)
L2:
Manawall
Convert
Blizzard
Thunder III
Sprint
Swiftcast
Flare
Aetherial Manipulation
R2:
Scathe
Fire III
Fire II
Fire
Thunder
Blizz III
Transpose
Raging Strikes
Expanded Hotbar L2+R2/R2+L2
Manaward
Apocatastasis
Eye for an Eye
Virus
Poisoning Potion
Intellegence Potion
Quelling Strikes
Face Target Macro (This is very important in my opinion. If I start casting an ability and a mob is on the move, I will spam this macro to face the target, preventing spell interruption)
Finally my last hot bar is all the spells I rarely use like Freeze, Lethary, Sleep, etc. Most of my secondary hot bar is just a duplicate of the main. So if I need to use sleep for example, I will still have my fire spells in the same position so I can spam the next attack and switch back to main hot bar when its more convenient.