The best way to begin your leatherworking career is to make a leather belt. This is because leather belts are the cheapest(dont take much leather) to make and you will most likely not fail. From then, get a piece of leather of high-ish QL and improve the belt until you need another tool. Keep improving it and you will gain skill. Once you have a higher chance on other items, make lots of gloves and improve them all to 15QL. Keep doing this with higher dificulty items and once your skill reaches 10-15. Try and stud some of them (it takes 0.2 kg of rivets to stud ALL leather items apart from leather pants which take 0.8 and leather jackets which take 0.4)
As your skill goes up you will need better QL tools.
Tool QL and skill level limits your max improving QL, not the raw leather QL.
==Lock Smithing==