It is always a good idea to keep a personal spelling list. You can make it your own vocabulary list too by giving the meaning of the words as well. Spelling doesn't happen by itself, you have to learn it. Reading, of course, also helps you learn how to spell. The more you read, the more words become familiar to you. However, when you are unsure, it is best to look a word up in the dictionary. (For the last sentence, you can either put what's above or you can put: "However, when you are unsure, it is best to look up a word in the dictionary.")
