there is nothing wrong with (striving) to improve your techniques- work at getting things as right as possible- but remind yourself (Only God can create perfection) and since you are not...
and if you stop & look around you---ever seen 2 leaves the same on a tree? or 2 flowers or 2 of anything???of course not- that is a lesson all it's own- strive for the overall beauty & don't try to be better than the only creator of perfection.