It's all chance, best thing to do is ask around about enchantment of the equip with people that already have it enchanted
There are no confirmed enchant success secrets, but there are definitely some ideas(like be at full troops, don't buy aqua/inferno because if will fail, etc) Also, Please put more efforts in your threads in the future, and put questions in the questions thread by Dillybar. Locking for low effort.