Do you have to double dig your new plants?
While it's true some people do hold "double digging" to be the gold standard, just as many have never done it and do fine with digging just a regular size hole. If double digging (digging a double sized hole) is important to you and you enjoy it, then continue.
But, you need to have fun in your garden in order to make sure that you maintain it. If you hold yourself to a standard you can't achieve, you will avoid the chores that are actually necessary and your garden will suffer. If you're starting a brand new garden in poor soil, double dig to your heart's content. Otherwise, continue as usual. If you're still worried, try the variegated Ajuga from our mail order catalog. That little guy is so easy to grow, it'd almost be embarrassed if you went to all that trouble just for it.