Any training tips

My dog just turned one last month and is an Australian Shepherd border collie so he picks up on commands pretty quickly. I’ve been trying to teach him to lay down which I know he knows what I’m saying as I tell him this at night and he does it but any other time when I tell him to do it he won’t unless I have a treat. I’ve tried giving him one every other time he does what I ask but again like I said if he knows I don’t have a treat in my hand he won’t do it. I also did try praising him vocally but he gets way too excited and after that it’s hard to get him to calm down. I plan on teaching him to do quite a bit of other things so any advice on how to train without having to use treats or how to get him to listen without expecting one?