What are your hints or suggestions to getting invisible or near invisible glue lines both with and against the grain of pieces of wood? For instance, if cut with a bandsaw, no sanding? Or sand then glue? I am at a loss with this one. Appreciate your help as I have students making bandsaw boxes and some glueups come out near impossible to see while others and I why especially when it is from the same chunk of wood and cut in similar manners.