all "spams" are easy to get if you follow these guidelines
1-Get the middle
you must always be on offense
2-Keep your enemy's economy at the minimum
simply make him retreat many times or kill them so that he'll retreat (remember though to do this only when you don't lose even a unit for it)
3-"Spam" a good offensive unit
very hard to disturb your enemy with sowrdswraths while he has castle archers
4-Make him retreat often
in this way you'll see if he hides some units (magikills, giants...) inside his castle
5-Kill his units
don't only focus on his miners: killing units is a good way to slow down his progress too (especially if he makes giants (kill them before they become more than 1-2)
6-Make some other different units
so that you can counter him if he does something (es. when spamming albows, make 2 ninja: if he uses a magikill he's done for)