I have heard "There's always a way", or "He has a knack for it.", but I have not heard "There's always a knack." A knack is a proclivity that an individual has for doing a certain thing. So it is really, kind of a personal thing. The person does it with their own style. So to say "There is always a knack" sounds a little odd to me.

My guess would be, based on the parenthetical statement beforehand, you more want to say something along the lines of, "There's always an easy way out." or, "There's always a shortcut." To really answer the question, however, I think we will need more context.