Just remember, bringing in a whole new character should only be a last resort if your original character or two aren't working out. Sometimes characters don't mesh up with what you want them to be, but you need to think carefully about a character's motivation, personality and background before bringing him into a story or roleplay. Make sure you want to devote time and development to that character, and don't consider him just a throw away, and you'll find yourself much more satisfied with the roleplaying experience without having to "throw away" someone or "bring someone new" in.