There are many different ways to do this, but I think the most common is to use the virtual switch that turns itself off immediately so it’s available for the next on.
There are two different ways to do this depending on the kind of Virtual you’re using.
If you are using a binary switch, one that stays on until you turn it off, just set up a separate “power allowance” smart lighting automation so that it will turn itself off after one minute. Then it’s available for the next “on.”
Note that you select your virtual switch and then say you want to turn it off, and then choose “power allowance exceeded” as the trigger.
The other way to do it is to use a momentary switch instead of a binary switch. A momentary switch is like a classic doorbell: it’s off most of the time, then when you turn it on it’s on for a moment, then it turns itself off again. Just choose “momentary button tile” as the device type when you create the virtual switch, and it will automatically have this behavior. 
Both ways work, it’s up to you which you want to use.