I agree. There are tons of resources out there that will tell you how to do it and typically they come with plenty of comments from other people telling why the particular example is wrong. From there you should be able to piece together a lot of the common mistakes, and understand how not to make them. If you can’t understand the why to any of them, perhaps it isn’t something you should be trying yourself.
Is it you and your memory just isn’t as good as it used to be?