I would strongly recommend following this
BST guide on wiki for solo spots. It got me to 75 (back when you could ONLY solo BST to 75). Now that exp is boosted you might even be able to stay at some more favorable camps longer.
Bismarck.Josiahfk said:
Sticking to a courier carrie is a great idea for most cases below 75.
You shouldn't use CC below 55. Use Crab Familiar if you need a crab for a jug pet. Just to clarify.