If you crate the pup while you're away, then sleep with a small blanket and then the next day, put that blanket in the crate with him/her. As long as the pup can smell you, he/she will become more secure. Also if the pup has a favorite toy, stuffed animals are usually good, make sure that is in there too. It may take a little time, but it has always worked for mine.

Just to start with, you should never leave a puppy for too long. As they need more bathroom breaks and alot more company. But it is a good idea to start training your puppy to get used to you not being around for those times you have to go out for a while. I would suggest that you do not make a fuss about leaving and returning. The idea is to not make a big deal out of leaving, so as your puppy thinks nothing of it. Dogs are pack animals, so being left alone is uncomfortable for them. So it's understandable your pup is upset about being left alone. Try to not have the same routine when you leave, for example, don't always grab your coat then keys and then bag before leaving. Your dog will recognise the routine and become more anxious about you leaving as it knows it will be left alone. Then just say something like 'goodbye' in an ordinary voice before going. When returning home do not go straight away to greet your dog. Take your time in greeting family member, and taking off your coat etc. After that you can go and greet your dog in calm manner, maybe just saying hello and stroking it before moving on. This will help the dog not become worried about you leaving, as it's emotions will not be heaightened when you leave or return. But it is a puppy, so try to remember it needs to learn. I would recommend giving it something to do whilst you are out. Like stuffing treats into a 'kong' toy, so as it has someting occupy its mind whilst you are away. It may not even notice you are gone. Giving it something like a blanket or stuffed animal with your scent, as already suggested, would also be a great help. It will give the animal something to curl up to and feel more protected because it will feel part of a 'pack' again. If your dog does something bad whilst you are out, such as chew something it shouldn't or toileted on the floor, ensure you do not shout at your dog on your return home. It will not associate what it has done earlier (chewing wires etc) with your shouting. Itwill only associate your anger with your return home, and it will begin to fear your return home. But remember to have lots of fun with your pup and I'm sure your dog will grow up into a very well mannered dog :)