"Suggest completions while typing." - No, Thanks

In XCode preferences under "Text Editing", there is a setting...

"Suggest completions while typing."

I recommend turning this off. I have always found the auto hints to get in the way at times. This puts them in a state where they are easily accessible but don't trip you up. You can always get your hints by hitting ESC. I have also found that it forces me to remember more of what I code. Cutting down reliance on code hints will make you a better developer. Use them as a tool, not a crutch.