In this game you should always be pumping villagers and building your economay steady.
even Rushing your economy should be on pace with your opponents even if your rush fails. When you rush you still kill some of there villies they still have to invest in soldiers to beat you off and they garrison villies in the tc or towers so lose out on resources while you don't. So unless you get obliterated. Always keep building your eco. A failed Rush really is'nt gonna set you back any further.
It really depends on what your opponent is doing alot of people who get rushed get paranoid and build up more units then they should expecting another wave in my expirience they don't usually push forward and it takes them a minute to get back on pace. so i tend to age up if i notice thats the case. And use cards to keep harrasing them. Just don't lose to many units harrassing the idea is to keep them on edge while you age. Then come in with superior troops. If they try to turtle IE put up alot of towers etc. Then i focus on my economy and prepare for a late game. Since they are wasting resources on towers etc. You can usually easliy get ahead of them in that regard build more mills etc. It just depend though on who you are playing with and what they are doing.